Look at a list of IC publications: 2019, 2018, 2017, 2016, 2015, 2014
2019 |
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Manna, Sara La; Roviello, Valentina; Scognamiglio, Pasqualina Liana; Diaferia, Carlo; Giannini, Cinzia; Sibillano, Teresa; Morelli, Giancarlo; Novellino, Ettore; Marasco, Daniela Amyloid fibers deriving from the aromatic core of C-terminal domain of nucleophosmin 1 Journal Article International Journal of Biological Macromolecules, 122 , pp. 517 - 525, 2019, ISSN: 0141-8130. @article{LAMANNA2019517, title = {Amyloid fibers deriving from the aromatic core of C-terminal domain of nucleophosmin 1}, author = {Sara La Manna and Valentina Roviello and Pasqualina Liana Scognamiglio and Carlo Diaferia and Cinzia Giannini and Teresa Sibillano and Giancarlo Morelli and Ettore Novellino and Daniela Marasco}, url = {http://www.sciencedirect.com/science/article/pii/S0141813018342004}, doi = {10.1016/j.ijbiomac.2018.10.210}, issn = {0141-8130}, year = {2019}, date = {2019-02-01}, journal = {International Journal of Biological Macromolecules}, volume = {122}, pages = {517 - 525}, abstract = {Nucleophosmin (NPM1) is the most frequently mutated gene in Acute Myeloid Leukemia (AML) patients and mutations lead to its aberrant cytoplasmatic accumulation in leukemic cells. Its C-terminal domain (CTD) is endowed with a globular structure consisting of a three-helix bundle in the wild type form that is disrupted by AML mutations. Our recent results demonstrate, unexpectedly and unequivocally, that regions of the CTD of NPM1 are prone to aggregate to amyloid states. Here we present novel studies, at solution as well as fibrillar states of a nonapeptide covering the 264–272 region of NPM1: this small fragment is the most amyloidogenic stretch of the entire protein and its conformational and aggregation properties were investigated through Circular Dichroism, Fluorescence spectroscopies, amyloid seeding assay (ASA), isothermal titration calorimetry (ITC) and electrospray ionization (ESI) mass analyses. Structural features of fibrils were investigated by means of Scanning Electron Microscopy (SEM) and Wide-Angle X-ray Scattering (WAXS). This study deepens the amyloid fibrillization process of a short stretch of the CTD likely involved in the propagative mechanism for NPMc+ cytoplasmatic accumulation in leukemogenesis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nucleophosmin (NPM1) is the most frequently mutated gene in Acute Myeloid Leukemia (AML) patients and mutations lead to its aberrant cytoplasmatic accumulation in leukemic cells. Its C-terminal domain (CTD) is endowed with a globular structure consisting of a three-helix bundle in the wild type form that is disrupted by AML mutations. Our recent results demonstrate, unexpectedly and unequivocally, that regions of the CTD of NPM1 are prone to aggregate to amyloid states. Here we present novel studies, at solution as well as fibrillar states of a nonapeptide covering the 264–272 region of NPM1: this small fragment is the most amyloidogenic stretch of the entire protein and its conformational and aggregation properties were investigated through Circular Dichroism, Fluorescence spectroscopies, amyloid seeding assay (ASA), isothermal titration calorimetry (ITC) and electrospray ionization (ESI) mass analyses. Structural features of fibrils were investigated by means of Scanning Electron Microscopy (SEM) and Wide-Angle X-ray Scattering (WAXS). This study deepens the amyloid fibrillization process of a short stretch of the CTD likely involved in the propagative mechanism for NPMc+ cytoplasmatic accumulation in leukemogenesis. | |
Yan, Robert; Yalinca, Havva; Paoletti, Francesca; Gobbo, Francesco; Marchetti, Laura; Kuzmanic, Antonija; Lamba, Doriano; Gervasio, Francesco Luigi; Konarev, Petr V; Cattaneo, Antonino; Pastore, Annalisa The Structure of the Pro-domain of Mouse proNGF in Contact with the NGF Domain Journal Article Structure, 27 (1), pp. 78 - 89.e3, 2019, ISSN: 0969-2126. @article{YAN201978, title = {The Structure of the Pro-domain of Mouse proNGF in Contact with the NGF Domain}, author = {Robert Yan and Havva Yalinca and Francesca Paoletti and Francesco Gobbo and Laura Marchetti and Antonija Kuzmanic and Doriano Lamba and Francesco Luigi Gervasio and Petr V Konarev and Antonino Cattaneo and Annalisa Pastore}, url = {http://www.sciencedirect.com/science/article/pii/S0969212618303605}, doi = {10.1016/j.str.2018.09.013}, issn = {0969-2126}, year = {2019}, date = {2019-01-01}, journal = {Structure}, volume = {27}, number = {1}, pages = {78 - 89.e3}, abstract = {Summary Nerve growth factor (NGF) is an important neurotrophic factor involved in the regulation of cell differentiation and survival of target neurons. Expressed as a proNGF precursor, NGF is matured by furin-mediated protease cleavage. Increasing evidence suggests that NGF and proNGF have distinct functional roles. While the structure of mature NGF is available, little is known about that of the pro-domain because of its dynamical structural features. We exploited an ad hoc hybrid strategy based on nuclear magnetic resonance and modeling validated by small-angle X-ray scattering to gain novel insights on the pro-domain, both in isolation and in the context of proNGF. We show that the isolated pro-domain is intrinsically unstructured but forms transient intramolecular contacts with mature NGF and has per se the ability to induce growth cone collapse, indicating functional independence. Our data represent an important step toward the structural and functional characterization of the properties of proNGF.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Summary Nerve growth factor (NGF) is an important neurotrophic factor involved in the regulation of cell differentiation and survival of target neurons. Expressed as a proNGF precursor, NGF is matured by furin-mediated protease cleavage. Increasing evidence suggests that NGF and proNGF have distinct functional roles. While the structure of mature NGF is available, little is known about that of the pro-domain because of its dynamical structural features. We exploited an ad hoc hybrid strategy based on nuclear magnetic resonance and modeling validated by small-angle X-ray scattering to gain novel insights on the pro-domain, both in isolation and in the context of proNGF. We show that the isolated pro-domain is intrinsically unstructured but forms transient intramolecular contacts with mature NGF and has per se the ability to induce growth cone collapse, indicating functional independence. Our data represent an important step toward the structural and functional characterization of the properties of proNGF. | |
Faiella, Giuliana; Simonetti, Marco; D'Uffizi, Antonio; Tipo, Vincenzo; Cesarelli, Mario; Clemente, Fabrizio Use of Modelling Simulation to Monitor the Performance of a Pediatric Emergency Department Inproceedings Lhotska, Lenka; Sukupova, Lucie; ć, Igor Lackovi; Ibbott, Geoffrey S (Ed.): World Congress on Medical Physics and Biomedical Engineering 2018, pp. 567–572, Springer Singapore, Singapore, 2019, ISBN: 978-981-10-9035-6. @inproceedings{10.1007/978-981-10-9035-6_105, title = {Use of Modelling Simulation to Monitor the Performance of a Pediatric Emergency Department}, author = {Giuliana Faiella and Marco Simonetti and Antonio D'Uffizi and Vincenzo Tipo and Mario Cesarelli and Fabrizio Clemente}, editor = {Lenka Lhotska and Lucie Sukupova and Igor Lackovi{ć} and Geoffrey S Ibbott}, url = {https://link.springer.com/chapter/10.1007%2F978-981-10-9035-6_105}, doi = {10.1007/978-981-10-9035-6_105}, isbn = {978-981-10-9035-6}, year = {2019}, date = {2019-01-01}, booktitle = {World Congress on Medical Physics and Biomedical Engineering 2018}, pages = {567--572}, publisher = {Springer Singapore}, address = {Singapore}, abstract = {Hospitals are complex systems in which different departments interact with each other. Systemic analytical models use systematic representations to facilitate the understanding of a complex process. The models are simulated with an imitation of the operations of a system and its internal processes, usually over time, and in appropriate detail. Simulation is used to study the performance of new systems as well as predict the effect of changes. Since Emergency Departments (ED) are unpredictable and frontline of healthcare service delivery, their detailed description and analysis are highly needed in order to design improvement actions. In this study, we will present the simulation of the ED a pediatric hospital which admits more than 100 k/year patients. The simulation tool is SIMIO®.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Hospitals are complex systems in which different departments interact with each other. Systemic analytical models use systematic representations to facilitate the understanding of a complex process. The models are simulated with an imitation of the operations of a system and its internal processes, usually over time, and in appropriate detail. Simulation is used to study the performance of new systems as well as predict the effect of changes. Since Emergency Departments (ED) are unpredictable and frontline of healthcare service delivery, their detailed description and analysis are highly needed in order to design improvement actions. In this study, we will present the simulation of the ED a pediatric hospital which admits more than 100 k/year patients. The simulation tool is SIMIO®. | |
2018 |
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Gijsbers, Abril; Montagut, Diana Carolina; Méndez-Godoy, Alfonso; Altamura, Davide; Saviano, Michele; Siliqi, Dritan; Sánchez-Puig, Nuria Interaction of the GTPase Elongation Factor Like-1 with the Shwachman-Diamond Syndrome Protein and Its Missense Mutations Journal Article International Journal of Molecular Sciences, 19 (12), 2018, ISSN: 1422-0067. @article{ijms19124012, title = {Interaction of the GTPase Elongation Factor Like-1 with the Shwachman-Diamond Syndrome Protein and Its Missense Mutations}, author = {Abril Gijsbers and Diana Carolina Montagut and Alfonso Méndez-Godoy and Davide Altamura and Michele Saviano and Dritan Siliqi and Nuria Sánchez-Puig}, url = {http://www.mdpi.com/1422-0067/19/12/4012}, doi = {10.3390/ijms19124012}, issn = {1422-0067}, year = {2018}, date = {2018-12-12}, journal = {International Journal of Molecular Sciences}, volume = {19}, number = {12}, abstract = {The Shwachman-Diamond Syndrome (SDS) is a disorder arising from mutations in the genes encoding for the Shwachman-Bodian-Diamond Syndrome (SBDS) protein and the GTPase known as Elongation Factor Like-1 (EFL1). Together, these proteins remove the anti-association factor eIF6 from the surface of the pre-60S ribosomal subunit to promote the formation of mature ribosomes. SBDS missense mutations can either destabilize the protein fold or affect surface epitopes. The molecular alterations resulting from the latter remain largely unknown, although some evidence suggest that binding to EFL1 may be affected. We further explored the effect of these SBDS mutations on the interaction with EFL1, and showed that all tested mutations disrupted the binding to EFL1. Binding was either severely weakened or almost abolished, depending on the assessed mutation. In higher eukaryotes, SBDS is essential for development, and lack of the protein results in early lethality. The existence of patients whose only source of SBDS consists of that with surface missense mutations highlights the importance of the interaction with EFL1 for their function. Additionally, we studied the interaction mechanism of the proteins in solution and demonstrated that binding consists of two independent and cooperative events, with domains 2–3 of SBDS directing the initial interaction with EFL1, followed by docking of domain 1. In solution, both proteins exhibited large flexibility and consisted of an ensemble of conformations, as demonstrated by Small Angle X-ray Scattering (SAXS) experiments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Shwachman-Diamond Syndrome (SDS) is a disorder arising from mutations in the genes encoding for the Shwachman-Bodian-Diamond Syndrome (SBDS) protein and the GTPase known as Elongation Factor Like-1 (EFL1). Together, these proteins remove the anti-association factor eIF6 from the surface of the pre-60S ribosomal subunit to promote the formation of mature ribosomes. SBDS missense mutations can either destabilize the protein fold or affect surface epitopes. The molecular alterations resulting from the latter remain largely unknown, although some evidence suggest that binding to EFL1 may be affected. We further explored the effect of these SBDS mutations on the interaction with EFL1, and showed that all tested mutations disrupted the binding to EFL1. Binding was either severely weakened or almost abolished, depending on the assessed mutation. In higher eukaryotes, SBDS is essential for development, and lack of the protein results in early lethality. The existence of patients whose only source of SBDS consists of that with surface missense mutations highlights the importance of the interaction with EFL1 for their function. Additionally, we studied the interaction mechanism of the proteins in solution and demonstrated that binding consists of two independent and cooperative events, with domains 2–3 of SBDS directing the initial interaction with EFL1, followed by docking of domain 1. In solution, both proteins exhibited large flexibility and consisted of an ensemble of conformations, as demonstrated by Small Angle X-ray Scattering (SAXS) experiments. | |
Italiano, Francesca; Agostiano, Angela; Belviso, Benny Danilo; Caliandro, Rocco; Carrozzini, Benedetta; Comparelli, Roberto; Melillo, Maria Teresa; Mesto, Ernesto; Tempesta, Gioacchino; Trotta, Massimo Colloids and Surfaces B: Biointerfaces, 172 , pp. 362 - 371, 2018, ISSN: 0927-7765. @article{ITALIANO2018362, title = {Interaction between the photosynthetic anoxygenic microorganism Rhodobacter sphaeroides and soluble gold compounds. From toxicity to gold nanoparticle synthesis}, author = {Francesca Italiano and Angela Agostiano and Benny Danilo Belviso and Rocco Caliandro and Benedetta Carrozzini and Roberto Comparelli and Maria Teresa Melillo and Ernesto Mesto and Gioacchino Tempesta and Massimo Trotta}, url = {http://www.sciencedirect.com/science/article/pii/S0927776518303813}, doi = {https://doi.org/10.1016/j.colsurfb.2018.06.010}, issn = {0927-7765}, year = {2018}, date = {2018-12-01}, journal = {Colloids and Surfaces B: Biointerfaces}, volume = {172}, pages = {362 - 371}, abstract = {Biological processes using microorganisms for nanoparticle synthesis are appealing as eco-friendly nanofactories. The response of the photosynthetic bacterium Rhodobacter sphaeroides to gold exposure and its reducing capability of Au(III) to produce stable gold nanoparticles (AuNPs), using metabolically active bacteria and quiescent biomass, is reported in this study. In the former case, bacterial cells were grown in presence of gold chloride at physiological pH. Gold exposure was found to cause a significant increase of the lag-phase duration at concentrations higher than 10 μM, suggesting the involvement of a resistance mechanism activated by Au(III). Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDS) analysis of bacterial cells confirmed the extracellular formation of AuNPs. Further studies were carried out on metabolically quiescent biomass incubated with gold chloride solution. The biosynthesized AuNPs were spherical in shape with an average size of 10 ± 3 nm, as analysed by Transmission Electron Microscopy (TEM). The nanoparticles were hydrophilic and stable against aggregation for several months. In order to identify the functional groups responsible for the reduction and stabilization of nanoparticles, AuNPs were analysed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), X-ray Fluorescence Spectrometry (XRF) and X-ray Absorption Spectroscopy (XAS) measurements. The obtained results indicate that gold ions bind to functional groups of cell membrane and are subsequently reduced by reducing sugars to gold nanoparticles and capped by a protein/peptide coat. Gold nanoparticles demonstrated to be efficient homogeneous catalysts in the degradation of nitroaromatic compounds.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biological processes using microorganisms for nanoparticle synthesis are appealing as eco-friendly nanofactories. The response of the photosynthetic bacterium Rhodobacter sphaeroides to gold exposure and its reducing capability of Au(III) to produce stable gold nanoparticles (AuNPs), using metabolically active bacteria and quiescent biomass, is reported in this study. In the former case, bacterial cells were grown in presence of gold chloride at physiological pH. Gold exposure was found to cause a significant increase of the lag-phase duration at concentrations higher than 10 μM, suggesting the involvement of a resistance mechanism activated by Au(III). Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDS) analysis of bacterial cells confirmed the extracellular formation of AuNPs. Further studies were carried out on metabolically quiescent biomass incubated with gold chloride solution. The biosynthesized AuNPs were spherical in shape with an average size of 10 ± 3 nm, as analysed by Transmission Electron Microscopy (TEM). The nanoparticles were hydrophilic and stable against aggregation for several months. In order to identify the functional groups responsible for the reduction and stabilization of nanoparticles, AuNPs were analysed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), X-ray Fluorescence Spectrometry (XRF) and X-ray Absorption Spectroscopy (XAS) measurements. The obtained results indicate that gold ions bind to functional groups of cell membrane and are subsequently reduced by reducing sugars to gold nanoparticles and capped by a protein/peptide coat. Gold nanoparticles demonstrated to be efficient homogeneous catalysts in the degradation of nitroaromatic compounds. | |
Carlino, Elvio; Scattarella, Francesco; Caro, Liberato De; Giannini, Cinzia; Siliqi, Dritan; Colombo, Alessandro; Galli, Davide Emilio Coherent Diffraction Imaging in Transmission Electron Microscopy for Atomic Resolution Quantitative Studies of the Matter Journal Article Materials, 11 (11), 2018, ISSN: 1996-1944. @article{ma11112323, title = {Coherent Diffraction Imaging in Transmission Electron Microscopy for Atomic Resolution Quantitative Studies of the Matter}, author = {Elvio Carlino and Francesco Scattarella and Liberato De Caro and Cinzia Giannini and Dritan Siliqi and Alessandro Colombo and Davide Emilio Galli}, url = {http://www.mdpi.com/1996-1944/11/11/2323}, doi = {10.3390/ma11112323}, issn = {1996-1944}, year = {2018}, date = {2018-11-19}, journal = {Materials}, volume = {11}, number = {11}, abstract = {The paper focuses on the development of electron coherent diffraction imaging in transmission electron microscopy, made in the, approximately, last ten years in our collaborative research group, to study the properties of materials at atomic resolution, overcoming the limitations due to the aberrations of the electron lenses and obtaining atomic resolution images, in which the distribution of the maxima is directly related to the specimen atomic potentials projected onto the microscope image detector. Here, it is shown how augmented coherent diffraction imaging makes it possible to achieve quantitative atomic resolution maps of the specimen atomic species, even in the presence of low atomic number atoms within a crystal matrix containing heavy atoms. This aim is achieved by: (i) tailoring the experimental set-up, (ii) improving the experimental data by properly treating parasitic diffused intensities to maximize the measure of the significant information, (iii) developing efficient methods to merge the information acquired in both direct and reciprocal spaces, (iv) treating the dynamical diffused intensities to accurately measure the specimen projected potentials, (v) improving the phase retrieval algorithms to better explore the space of solutions. Finally, some of the future perspectives of coherent diffraction imaging in a transmission electron microscope are given.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The paper focuses on the development of electron coherent diffraction imaging in transmission electron microscopy, made in the, approximately, last ten years in our collaborative research group, to study the properties of materials at atomic resolution, overcoming the limitations due to the aberrations of the electron lenses and obtaining atomic resolution images, in which the distribution of the maxima is directly related to the specimen atomic potentials projected onto the microscope image detector. Here, it is shown how augmented coherent diffraction imaging makes it possible to achieve quantitative atomic resolution maps of the specimen atomic species, even in the presence of low atomic number atoms within a crystal matrix containing heavy atoms. This aim is achieved by: (i) tailoring the experimental set-up, (ii) improving the experimental data by properly treating parasitic diffused intensities to maximize the measure of the significant information, (iii) developing efficient methods to merge the information acquired in both direct and reciprocal spaces, (iv) treating the dynamical diffused intensities to accurately measure the specimen projected potentials, (v) improving the phase retrieval algorithms to better explore the space of solutions. Finally, some of the future perspectives of coherent diffraction imaging in a transmission electron microscope are given. | |
Coscia, Ubaldo; Ambrosone, Giuseppina; Palomba, Mariano; Binetti, Simona; Donne, Alessia Le; Siliqi, Dritan; Carotenuto, Gianfranco Photoconductivity of tellurium-poly(methyl methacrylate) in the ultraviolet–visible-near infrared range Journal Article Applied Surface Science, 457 , pp. 229 - 234, 2018, ISSN: 0169-4332. @article{COSCIA2018229, title = {Photoconductivity of tellurium-poly(methyl methacrylate) in the ultraviolet–visible-near infrared range}, author = {Ubaldo Coscia and Giuseppina Ambrosone and Mariano Palomba and Simona Binetti and Alessia Le Donne and Dritan Siliqi and Gianfranco Carotenuto}, url = {http://www.sciencedirect.com/science/article/pii/S0169433218317896}, doi = {https://doi.org/10.1016/j.apsusc.2018.06.221}, issn = {0169-4332}, year = {2018}, date = {2018-11-01}, journal = {Applied Surface Science}, volume = {457}, pages = {229 - 234}, abstract = {Fine powders composed of tellurium grains of average size <10 nm were produced by dry vibration milling combined with liquid-phase sedimentation techniques, starting from polycrystalline powders with average grain diameter of ca. 30 μm. Nanocomposite films were obtained by binding the nanosized tellurium grains with poly(methyl methacrylate). Raman spectroscopy revealed that the films were based on the coexistence of tellurium and tellurium oxide crystalline phases due to a partial oxidation in air of the grains. The optical measurements of the fabricated material showed that the absorbance was nearly constant in the 310–2200 nm range and that a typical UV absorption peak of the nanostructured tellurium was centered at around 260 nm. An extensive characterization of the photoconductivity properties was carried out by illuminating the tellurium-poly(methyl methacrylate) films with white light or radiations of different spectral composition selected from the UV–Vis-NIR region. Data analysis has allowed to demonstrate that the photoresponse is closely related to the optical absorption and is independent of the spectral composition of the incident radiation in the wavelength range from 310 to 2200 nm, while the photocurrent increases linearly as a function of the optical power density over about three orders of magnitude.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fine powders composed of tellurium grains of average size <10 nm were produced by dry vibration milling combined with liquid-phase sedimentation techniques, starting from polycrystalline powders with average grain diameter of ca. 30 μm. Nanocomposite films were obtained by binding the nanosized tellurium grains with poly(methyl methacrylate). Raman spectroscopy revealed that the films were based on the coexistence of tellurium and tellurium oxide crystalline phases due to a partial oxidation in air of the grains. The optical measurements of the fabricated material showed that the absorbance was nearly constant in the 310–2200 nm range and that a typical UV absorption peak of the nanostructured tellurium was centered at around 260 nm. An extensive characterization of the photoconductivity properties was carried out by illuminating the tellurium-poly(methyl methacrylate) films with white light or radiations of different spectral composition selected from the UV–Vis-NIR region. Data analysis has allowed to demonstrate that the photoresponse is closely related to the optical absorption and is independent of the spectral composition of the incident radiation in the wavelength range from 310 to 2200 nm, while the photocurrent increases linearly as a function of the optical power density over about three orders of magnitude. | |
Mishra, Annu; Narang, Jagriti; Pundir, Chandra Shekhar; Pilloton, Roberto; Khanuja, Manika Morphology-Preferable MoSe2 Nanobrooms as a Sensing Platform for Highly Selective Apta-Capturing of Salmonella Bacteria Journal Article ACS Omega, 3 (10), pp. 13020-13027, 2018. @article{doi:10.1021/acsomega.8b01074, title = {Morphology-Preferable MoSe2 Nanobrooms as a Sensing Platform for Highly Selective Apta-Capturing of Salmonella Bacteria}, author = {Annu Mishra and Jagriti Narang and Chandra Shekhar Pundir and Roberto Pilloton and Manika Khanuja}, url = {https://doi.org/10.1021/acsomega.8b01074}, doi = {10.1021/acsomega.8b01074}, year = {2018}, date = {2018-10-11}, journal = {ACS Omega}, volume = {3}, number = {10}, pages = {13020-13027}, abstract = {The present report employed nanobroom (NB)-shaped two-dimensional molybdenum diselenide (MoSe2) for the preparation of a sensing matrix for the detection of Salmonella paratyphi. An aptamer specific to salmonella was immobilized onto MoSe2NB-modified fluorine-doped tin oxide via glutaraldehyde cross-linking. Structural and morphological characterizations were performed using UV–vis spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques. Characterizations confirmed the nanobroom morphology and nanosize of the MoSe2 material. Electrochemical studies revealed a good linear detection range of 10–2–10–10 CFU/mL with low detection limit of 1 × 10–10 CFU/mL and with R2 = 0.98. The developed preferable nanobroom-shaped sensing matrix can provide a promising platform for rapid and accurate detection of Salmonella in real samples due to its tremendous stability and sensitivity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present report employed nanobroom (NB)-shaped two-dimensional molybdenum diselenide (MoSe2) for the preparation of a sensing matrix for the detection of Salmonella paratyphi. An aptamer specific to salmonella was immobilized onto MoSe2NB-modified fluorine-doped tin oxide via glutaraldehyde cross-linking. Structural and morphological characterizations were performed using UV–vis spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques. Characterizations confirmed the nanobroom morphology and nanosize of the MoSe2 material. Electrochemical studies revealed a good linear detection range of 10–2–10–10 CFU/mL with low detection limit of 1 × 10–10 CFU/mL and with R2 = 0.98. The developed preferable nanobroom-shaped sensing matrix can provide a promising platform for rapid and accurate detection of Salmonella in real samples due to its tremendous stability and sensitivity. |  |
Moglianetti, Mauro; Solla-Gullón, José; Donati, Paolo; Pedone, Deborah; Debellis, Doriana; Sibillano, Teresa; Brescia, Rosaria; Giannini, Cinzia; Montiel, Vicente; Feliu, Juan M; Pompa, Pier Paolo Citrate-Coated, Size-Tunable Octahedral Platinum Nanocrystals: A Novel Route for Advanced Electrocatalysts Journal Article ACS Applied Materials & Interfaces, 10 (48), pp. 41608-41617, 2018. @article{doi:10.1021/acsami.8b11774, title = {Citrate-Coated, Size-Tunable Octahedral Platinum Nanocrystals: A Novel Route for Advanced Electrocatalysts}, author = {Mauro Moglianetti and José Solla-Gullón and Paolo Donati and Deborah Pedone and Doriana Debellis and Teresa Sibillano and Rosaria Brescia and Cinzia Giannini and Vicente Montiel and Juan M Feliu and Pier Paolo Pompa}, url = {https://doi.org/10.1021/acsami.8b11774}, doi = {10.1021/acsami.8b11774}, year = {2018}, date = {2018-10-08}, journal = {ACS Applied Materials & Interfaces}, volume = {10}, number = {48}, pages = {41608-41617}, abstract = {The development of green and scalable syntheses for the preparation of size- and shape-controlled metal nanocrystals is of high interest in many areas, including catalysis, electrocatalysis, nanomedicine, and electronics. In this work, a new synthetic approach based on the synergistic action of physical parameters and reagents produces size-tunable octahedral Pt nanocrystals, without the use of catalyst-poisoning reagents and/or difficult-to-remove coatings. The synthesis requires sodium citrate, ascorbic acid, and fine control of the reduction rate in aqueous environment. Pt octahedral nanocrystals with particle size as low as 7 nm and highly developed 111 facets have been achieved, as demonstrated by transmission electron microscopy, X-ray diffraction, and electrochemical methods. The absence of sticky molecules together with the high quality of the surface makes these nanocrystals ideal candidates in electrocatalysis. Notably, 7 nm bismuth-decorated octahedral nanocrystals exhibit superior performance for the electrooxidation of formic acid in terms of both specific and mass activities.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of green and scalable syntheses for the preparation of size- and shape-controlled metal nanocrystals is of high interest in many areas, including catalysis, electrocatalysis, nanomedicine, and electronics. In this work, a new synthetic approach based on the synergistic action of physical parameters and reagents produces size-tunable octahedral Pt nanocrystals, without the use of catalyst-poisoning reagents and/or difficult-to-remove coatings. The synthesis requires sodium citrate, ascorbic acid, and fine control of the reduction rate in aqueous environment. Pt octahedral nanocrystals with particle size as low as 7 nm and highly developed 111 facets have been achieved, as demonstrated by transmission electron microscopy, X-ray diffraction, and electrochemical methods. The absence of sticky molecules together with the high quality of the surface makes these nanocrystals ideal candidates in electrocatalysis. Notably, 7 nm bismuth-decorated octahedral nanocrystals exhibit superior performance for the electrooxidation of formic acid in terms of both specific and mass activities. |  |
Antonacci, Amina; Lambreva, Maya D; Margonelli, Andrea; Sobolev, Anatoly P; Pastorelli, Sandro; Bertalan, Ivo; Johanningmeier, Udo; Sobolev, Vladimir; Samish, Ilan; Edelman, Marvin; Havurinne, Vesa; Tyystjärvi, Esa; Giardi, Maria T; Mattoo, Autar K; Rea, Giuseppina Photosystem-II D1 protein mutants of Chlamydomonas reinhardtii in relation to metabolic rewiring and remodelling of H-bond network at QB site Journal Article Scientific Reports, 8 , pp. 14745, 2018. @article{Antonacci2018, title = {Photosystem-II D1 protein mutants of Chlamydomonas reinhardtii in relation to metabolic rewiring and remodelling of H-bond network at QB site}, author = {Amina Antonacci and Maya D. Lambreva and Andrea Margonelli and Anatoly P. Sobolev and Sandro Pastorelli and Ivo Bertalan and Udo Johanningmeier and Vladimir Sobolev and Ilan Samish and Marvin Edelman and Vesa Havurinne and Esa Tyystjärvi and Maria T. Giardi and Autar K. Mattoo and Giuseppina Rea }, url = {https://doi.org/10.1038/s41598-018-33146-y}, doi = {10.1038/s41598-018-33146-y}, year = {2018}, date = {2018-10-03}, journal = {Scientific Reports}, volume = {8}, pages = {14745}, abstract = {Photosystem II (PSII) reaction centre D1 protein of oxygenic phototrophs is pivotal for sustaining photosynthesis. Also, it is targeted by herbicides and herbicide-resistant weeds harbour single amino acid substitutions in D1. Conservation of D1 primary structure is seminal in the photosynthetic performance in many diverse species. In this study, we analysed built-in and environmentally-induced (high temperature and high photon fluency – HT/HL) phenotypes of two D1 mutants of Chlamydomonas reinhardtii with Ala250Arg (A250R) and Ser264Lys (S264K) substitutions. Both mutations differentially affected efficiency of electron transport and oxygen production. In addition, targeted metabolomics revealed that the mutants undergo specific differences in primary and secondary metabolism, namely, amino acids, organic acids, pigments, NAD, xanthophylls and carotenes. Levels of lutein, β-carotene and zeaxanthin were in sync with their corresponding gene transcripts in response to HT/HL stress treatment in the parental (IL) and A250R strains. D1 structure analysis indicated that, among other effects, remodelling of H-bond network at the QB site might underpin the observed phenotypes. Thus, the D1 protein, in addition to being pivotal for efficient photosynthesis, may have a moonlighting role in rewiring of specific metabolic pathways, possibly involving retrograde signalling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Photosystem II (PSII) reaction centre D1 protein of oxygenic phototrophs is pivotal for sustaining photosynthesis. Also, it is targeted by herbicides and herbicide-resistant weeds harbour single amino acid substitutions in D1. Conservation of D1 primary structure is seminal in the photosynthetic performance in many diverse species. In this study, we analysed built-in and environmentally-induced (high temperature and high photon fluency – HT/HL) phenotypes of two D1 mutants of Chlamydomonas reinhardtii with Ala250Arg (A250R) and Ser264Lys (S264K) substitutions. Both mutations differentially affected efficiency of electron transport and oxygen production. In addition, targeted metabolomics revealed that the mutants undergo specific differences in primary and secondary metabolism, namely, amino acids, organic acids, pigments, NAD, xanthophylls and carotenes. Levels of lutein, β-carotene and zeaxanthin were in sync with their corresponding gene transcripts in response to HT/HL stress treatment in the parental (IL) and A250R strains. D1 structure analysis indicated that, among other effects, remodelling of H-bond network at the QB site might underpin the observed phenotypes. Thus, the D1 protein, in addition to being pivotal for efficient photosynthesis, may have a moonlighting role in rewiring of specific metabolic pathways, possibly involving retrograde signalling. | |
Bolzati, Cristina; Salvarese, Nicola; Carpanese, Debora; Seraglia, Roberta; Meléndez-Alafort, Laura; Rosato, Antonio; Capasso, Domenica; Saviano, Michele; Gatto, Annarita Del; Comegna, Daniela; Zaccaro, Laura Journal of Medicinal Chemistry, 61 (21), pp. 9596-9610, 2018, (PMID: 30278131). @article{doi:10.1021/acs.jmedchem.8b01075, title = {[99mTc][Tc(N)PNP43]-Labeled RGD Peptides As New Probes for a Selective Detection of αvβ3 Integrin: Synthesis, Structure–Activity and Pharmacokinetic Studies}, author = {Cristina Bolzati and Nicola Salvarese and Debora Carpanese and Roberta Seraglia and Laura Meléndez-Alafort and Antonio Rosato and Domenica Capasso and Michele Saviano and Annarita Del Gatto and Daniela Comegna and Laura Zaccaro}, url = {https://doi.org/10.1021/acs.jmedchem.8b01075}, doi = {10.1021/acs.jmedchem.8b01075}, year = {2018}, date = {2018-10-02}, journal = {Journal of Medicinal Chemistry}, volume = {61}, number = {21}, pages = {9596-9610}, abstract = {New integrin-selective molecules suitable for therapeutic or imaging purposes are currently of interest in development of effective personalized medical platforms. RGDechi is a bifunctional peptide selective for integrin αvβ3. Herein, RGDechi and three truncated derivatives functionalized with a cysteine (1–4) were synthesized and labeled with the [99mTc][Tc(N)PNP43]-synthon ([PNP43 = (CH3)2P(CH2)2N(C2H4OCH3)(CH2)2P(CH3)2]) (99mTc1–4) as a basis for selective integrin recognition. The pharmacological parameters of all radiolabeled peptides were assessed along with the pharmacokinetic profiles of the most promising 99mTc1 and 99mTc2 compounds both on healthy and melanoma-bearing mice. Their metabolism and metabolite identification are also reported. 99mTc1–2 are able to discriminate between endogenously expressed integrins αvβ3 and αvβ5 and possess favorable pharmacokinetics characterized by low liver uptake and rapid elimination from nontarget tissues resulting in positive target-to-nontarget ratios. Results are encouraging; the presented construct can be considered the starting point for the development of agents for the selective detection of αvβ3 expression by SPECT.}, note = {PMID: 30278131}, keywords = {}, pubstate = {published}, tppubtype = {article} } New integrin-selective molecules suitable for therapeutic or imaging purposes are currently of interest in development of effective personalized medical platforms. RGDechi is a bifunctional peptide selective for integrin αvβ3. Herein, RGDechi and three truncated derivatives functionalized with a cysteine (1–4) were synthesized and labeled with the [99mTc][Tc(N)PNP43]-synthon ([PNP43 = (CH3)2P(CH2)2N(C2H4OCH3)(CH2)2P(CH3)2]) (99mTc1–4) as a basis for selective integrin recognition. The pharmacological parameters of all radiolabeled peptides were assessed along with the pharmacokinetic profiles of the most promising 99mTc1 and 99mTc2 compounds both on healthy and melanoma-bearing mice. Their metabolism and metabolite identification are also reported. 99mTc1–2 are able to discriminate between endogenously expressed integrins αvβ3 and αvβ5 and possess favorable pharmacokinetics characterized by low liver uptake and rapid elimination from nontarget tissues resulting in positive target-to-nontarget ratios. Results are encouraging; the presented construct can be considered the starting point for the development of agents for the selective detection of αvβ3 expression by SPECT. | ![[99mTc][Tc(N)PNP43]-Labeled RGD Peptides As New Probes for a Selective Detection of αvβ3 Integrin: Synthesis, Structure–Activity and Pharmacokinetic Studies](https://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jmcmar/2018/jmcmar.2018.61.issue-21/acs.jmedchem.8b01075/20181101/images/medium/jm-2018-01075k_0007.gif) |
White, Ian K; Bugris, Valeria; McCarthy, Andrew A; Ravelli, Raimond B G; Csankó, Krisztián; Cassetta, Alberto; Brockhauser, Sandor Calibration of rotation axes for multi-axis goniometers in macromolecular crystallography Journal Article Journal of Applied Crystallography, 51 (5), pp. 1421–1427, 2018. @article{White:ap5028, title = {Calibration of rotation axes for multi-axis goniometers in macromolecular crystallography}, author = {Ian K White and Valeria Bugris and Andrew A McCarthy and Raimond B G Ravelli and Krisztián Csankó and Alberto Cassetta and Sandor Brockhauser}, url = {https://doi.org/10.1107/S1600576718010956}, doi = {10.1107/S1600576718010956}, year = {2018}, date = {2018-10-01}, journal = {Journal of Applied Crystallography}, volume = {51}, number = {5}, pages = {1421--1427}, abstract = {The installation of multi-axis goniometers such as the ESRF/EMBL miniKappa goniometer system has allowed the increased use of sample reorientation in macromolecular crystallography. Old and newly appearing data collection methods require precision and accuracy in crystal reorientation. The proper use of such multi-axis systems has necessitated the development of rapid and easy to perform methods for establishing and evaluating device calibration. A new diffraction-based method meeting these criteria has been developed for the calibration of the motors responsible for rotational motion. This method takes advantage of crystal symmetry by comparing the orientations of a sample rotated about a given axis and checking that the magnitude of the real rotation fits the calculated angle between these two orientations. Hence, the accuracy and precision of rotational motion can be assessed. This rotation calibration procedure has been performed on several beamlines at the ESRF and other synchrotrons. Some resulting data are presented here for reference.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The installation of multi-axis goniometers such as the ESRF/EMBL miniKappa goniometer system has allowed the increased use of sample reorientation in macromolecular crystallography. Old and newly appearing data collection methods require precision and accuracy in crystal reorientation. The proper use of such multi-axis systems has necessitated the development of rapid and easy to perform methods for establishing and evaluating device calibration. A new diffraction-based method meeting these criteria has been developed for the calibration of the motors responsible for rotational motion. This method takes advantage of crystal symmetry by comparing the orientations of a sample rotated about a given axis and checking that the magnitude of the real rotation fits the calculated angle between these two orientations. Hence, the accuracy and precision of rotational motion can be assessed. This rotation calibration procedure has been performed on several beamlines at the ESRF and other synchrotrons. Some resulting data are presented here for reference. |  |
Turemis, M; Silletti, S; Pezzotti, G; Sanchís, J; Farré, M; Giardi, M T Optical biosensor based on the microalga-paramecium symbiosis for improved marine monitoring Journal Article Sensors and Actuators, B: Chemical, 270 , pp. 424-432, 2018, (cited By 0). @article{Turemis2018424, title = {Optical biosensor based on the microalga-paramecium symbiosis for improved marine monitoring}, author = {M Turemis and S Silletti and G Pezzotti and J Sanchís and M Farré and M T Giardi}, url = {https://www.sciencedirect.com/science/article/pii/S0925400518308153?via%3Dihub}, doi = {10.1016/j.snb.2018.04.111}, year = {2018}, date = {2018-10-01}, journal = {Sensors and Actuators, B: Chemical}, volume = {270}, pages = {424-432}, abstract = {Unprecedented increases in anthropogenic pollution of marine environments have made the development of sensitive, cheap, and adaptable early-warning systems absolutely crucial for on-site monitoring of chemical contaminants. Biosensors based on microalgae cells might constitute a promising and cost-effective alternative for environmental analyses since they capable of providing rapid toxicity information in the case of pollution, while assessing the harmful effects of the contaminants on the ecosystem. In this work, an optical biosensor, based on an array of algal biomediators, has been developed to monitor relevant marine pollutants. A pre-study was performed to select the most suitable biomediator for measurements of pesticides in marine water. The potential of the algae-protozoa symbiotic association between Chlorella vulgaris and the ciliate Tetrahymena pyriformis as a sensitive biomediator for biosensor development was assessed, showing enhanced resistance to marine water salinity compared to free-living algae strains. The symbiotic strain was entrapped in calcium-alginate within newly developed fluidic flow cells with integrated detectors for real-time detection of marine pollutants by fluorescence analysis of photosynthetic photosystem II. The biosensor response was examined in the presence of three commonly found pesticides—simazine, atrazine and diuron—alone or in combination, and the results were compared by liquid chromatography-mass spectrometry. The limits of detection for the three herbicides were 1.35, 0.44, and 0.25 μg/L respectively, and 0.13 μg/L for the mixture. In summary, an autonomous integrated symbiotic association of paramecium-chlorella-based biosensor was successfully developed for real-time monitoring of marine water and evaluation of biotoxicity.}, note = {cited By 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Unprecedented increases in anthropogenic pollution of marine environments have made the development of sensitive, cheap, and adaptable early-warning systems absolutely crucial for on-site monitoring of chemical contaminants. Biosensors based on microalgae cells might constitute a promising and cost-effective alternative for environmental analyses since they capable of providing rapid toxicity information in the case of pollution, while assessing the harmful effects of the contaminants on the ecosystem. In this work, an optical biosensor, based on an array of algal biomediators, has been developed to monitor relevant marine pollutants. A pre-study was performed to select the most suitable biomediator for measurements of pesticides in marine water. The potential of the algae-protozoa symbiotic association between Chlorella vulgaris and the ciliate Tetrahymena pyriformis as a sensitive biomediator for biosensor development was assessed, showing enhanced resistance to marine water salinity compared to free-living algae strains. The symbiotic strain was entrapped in calcium-alginate within newly developed fluidic flow cells with integrated detectors for real-time detection of marine pollutants by fluorescence analysis of photosynthetic photosystem II. The biosensor response was examined in the presence of three commonly found pesticides—simazine, atrazine and diuron—alone or in combination, and the results were compared by liquid chromatography-mass spectrometry. The limits of detection for the three herbicides were 1.35, 0.44, and 0.25 μg/L respectively, and 0.13 μg/L for the mixture. In summary, an autonomous integrated symbiotic association of paramecium-chlorella-based biosensor was successfully developed for real-time monitoring of marine water and evaluation of biotoxicity. | |
Algieri, Luciana; Todaro, Maria Teresa; Guido, Francesco; Mastronardi, Vincenzo; Desmaële, Denis; Qualtieri, Antonio; Giannini, Cinzia; Sibillano, Teresa; Vittorio, Massimo De Flexible Piezoelectric Energy-Harvesting Exploiting Biocompatible AlN Thin Films Grown onto Spin-Coated Polyimide Layers Journal Article ACS Applied Energy Materials, 1 (10), pp. 5203-5210, 2018. @article{doi:10.1021/acsaem.8b00820, title = {Flexible Piezoelectric Energy-Harvesting Exploiting Biocompatible AlN Thin Films Grown onto Spin-Coated Polyimide Layers}, author = {Luciana Algieri and Maria Teresa Todaro and Francesco Guido and Vincenzo Mastronardi and Denis Desmaële and Antonio Qualtieri and Cinzia Giannini and Teresa Sibillano and Massimo De Vittorio}, url = {https://doi.org/10.1021/acsaem.8b00820}, doi = {10.1021/acsaem.8b00820}, year = {2018}, date = {2018-09-19}, journal = {ACS Applied Energy Materials}, volume = {1}, number = {10}, pages = {5203-5210}, abstract = {The increasing demand of piezoelectric energy harvesters for wearable and implantable applications requires biocompatible materials and careful structural device design, paying special attention to the conformability characteristics, properly tailored to scavenge continuously electrical energy even from the tiniest body movements. This paper provides a comprehensive study on a flexible and biocompatible aluminum nitride (AlN) energy harvester based on a new alternative fabrication approach, exploiting a thin polyimide (PI) substrate, prepared by spin coating of precursors solution. This strategy allows manufacturing substrates with adjustable thickness to meet conformability requirements. The device is based on a piezoelectric AlN thin film, sputtered directly onto the soft PI substrate, without poling/annealing processes and patterned by simple and low cost microfabrication technologies. AlN active layer, grown on soft substrate, exhibits good morphological and structural properties with roughness root mean squared (Rrms) of 6.35 nm, columnar texture and (002) c-axis orientation. Additionally, piezoelectric characterization has been performed and the extracted piezoelectric coefficient value of AlN thin film resulted to be 4.93 ± 0.09 pm/V. The fabricated flexible AlN energy harvester generates an output peak-to-peak voltage of ∼1.4 V and a peak-to-peak current up to 1.6 μA, under periodical deformation, corresponding to a current density of 2.1 μA/cm2, and providing a maximum generated power of 1.57 μW under optimal resistive load. Furthermore, the AlN energy harvester exhibits high elasticity and resistance to mechanical fatigue. High quality AlN piezoelectric layers on elastic substrates with tunable thicknesses pave the way for the development of a straightforward technological platform for wearable/implantable energy harvesters and biomechanical sensors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The increasing demand of piezoelectric energy harvesters for wearable and implantable applications requires biocompatible materials and careful structural device design, paying special attention to the conformability characteristics, properly tailored to scavenge continuously electrical energy even from the tiniest body movements. This paper provides a comprehensive study on a flexible and biocompatible aluminum nitride (AlN) energy harvester based on a new alternative fabrication approach, exploiting a thin polyimide (PI) substrate, prepared by spin coating of precursors solution. This strategy allows manufacturing substrates with adjustable thickness to meet conformability requirements. The device is based on a piezoelectric AlN thin film, sputtered directly onto the soft PI substrate, without poling/annealing processes and patterned by simple and low cost microfabrication technologies. AlN active layer, grown on soft substrate, exhibits good morphological and structural properties with roughness root mean squared (Rrms) of 6.35 nm, columnar texture and (002) c-axis orientation. Additionally, piezoelectric characterization has been performed and the extracted piezoelectric coefficient value of AlN thin film resulted to be 4.93 ± 0.09 pm/V. The fabricated flexible AlN energy harvester generates an output peak-to-peak voltage of ∼1.4 V and a peak-to-peak current up to 1.6 μA, under periodical deformation, corresponding to a current density of 2.1 μA/cm2, and providing a maximum generated power of 1.57 μW under optimal resistive load. Furthermore, the AlN energy harvester exhibits high elasticity and resistance to mechanical fatigue. High quality AlN piezoelectric layers on elastic substrates with tunable thicknesses pave the way for the development of a straightforward technological platform for wearable/implantable energy harvesters and biomechanical sensors. |  |
Diaferia, Carlo; Balasco, Nicole; Altamura, Davide; Sibillano, Teresa; Gallo, Enrico; Roviello, Valentina; Giannini, Cinzia; Morelli, Giancarlo; Vitagliano, Luigi; Accardo, Antonella Assembly modes of hexaphenylalanine variants as function of the charge states of their terminal ends Journal Article Soft Matter, 14 , pp. 8219-8230, 2018. @article{C8SM01441H, title = {Assembly modes of hexaphenylalanine variants as function of the charge states of their terminal ends}, author = {Carlo Diaferia and Nicole Balasco and Davide Altamura and Teresa Sibillano and Enrico Gallo and Valentina Roviello and Cinzia Giannini and Giancarlo Morelli and Luigi Vitagliano and Antonella Accardo}, url = {http://dx.doi.org/10.1039/C8SM01441H}, doi = {10.1039/C8SM01441H}, year = {2018}, date = {2018-09-04}, journal = {Soft Matter}, volume = {14}, pages = {8219-8230}, publisher = {The Royal Society of Chemistry}, abstract = {The ability of peptides to self-assemble represents a valuable tool for the development of biomaterials of biotechnological and/or biomedical interest. Diphenylalanine homodimer (FF) and its analogues are among the most promising systems in this field. The longest Phe-based building block hitherto characterized is pentaphenylalanine (F5). We studied the aggregation propensity and the structural/morphological features of assemblies of zwitterionic hexaphenylalanine H+-F6-O− and of three variants characterized by different charged states of the terminal ends (Ac-F6-Amide, H+-F6-Amide and Ac-F6-O−). As previously observed for PEGylated hexaphenylalanine (PEG8-F6), all F6 variants show a strong tendency to form β-rich assemblies in which the structural motif is constituted by antiparallel β-strands in the cross-β framework. Extensive replica exchange molecular dynamics simulations carried out on a pairs of F6 peptides indicate that the antiparallel β-structure of the final assemblies is likely dictated by the preferred association modes of the individual chains in the very early stages of the aggregation process. Our data suggest that even very small F6 peptides are properly pre-organized and prone to the build-up of the final assembly.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability of peptides to self-assemble represents a valuable tool for the development of biomaterials of biotechnological and/or biomedical interest. Diphenylalanine homodimer (FF) and its analogues are among the most promising systems in this field. The longest Phe-based building block hitherto characterized is pentaphenylalanine (F5). We studied the aggregation propensity and the structural/morphological features of assemblies of zwitterionic hexaphenylalanine H+-F6-O− and of three variants characterized by different charged states of the terminal ends (Ac-F6-Amide, H+-F6-Amide and Ac-F6-O−). As previously observed for PEGylated hexaphenylalanine (PEG8-F6), all F6 variants show a strong tendency to form β-rich assemblies in which the structural motif is constituted by antiparallel β-strands in the cross-β framework. Extensive replica exchange molecular dynamics simulations carried out on a pairs of F6 peptides indicate that the antiparallel β-structure of the final assemblies is likely dictated by the preferred association modes of the individual chains in the very early stages of the aggregation process. Our data suggest that even very small F6 peptides are properly pre-organized and prone to the build-up of the final assembly. |  |