S. Fermani - Academia.edu (original) (raw)

Papers by S. Fermani

ABSTRACTProtein aggregation is a complex physiological process, primarily determined by stress-re... more ABSTRACTProtein aggregation is a complex physiological process, primarily determined by stress-related factors revealing the hidden aggregation propensity of proteins that otherwise are fully soluble. Here we report a mechanism by which glycolytic glyceraldehyde-3-phosphate dehydrogenase of Arabidopsis thaliana (AtGAPC1) is primed to form insoluble aggregates by the glutathionylation of its catalytic cysteine (Cys149). Following a lag phase, glutathionylated AtGAPC1 initiates a self-aggregation process resulting in the formation of branched chains of globular particles made of partially misfolded and totally inactive proteins. GSH molecules within AtGAPC1 active sites are suggested to provide the initial destabilizing signal. The following removal of glutathione by the formation of an alternative disulfide bond between Cys149 and Cys153 reinforces the aggregation process. Besides acting as a protective mechanism against overoxidation, S-glutathionylation of AtGAPC1 triggers an unexp...

CrystEngComm, 2017

Materials and Methods Materials Analytical grade chemicals, calcium chloride (CaCl 2), sodium car... more Materials and Methods Materials Analytical grade chemicals, calcium chloride (CaCl 2), sodium carbonate (Na 2 CO 3) and magnesium chloride (MgCl 2) (all Sigma Aldrich) and high quality deionized water (conductivity less than 0.055 μS cm-1) were used in order to prepare the stock solutions. The reactant solutions were prepared by appropriate dilution of respective stock. Precipitation systems Precipitation systems in which predominantly heterogeneous nucleation were investigated. The actual supersaturation, expressed with respect to aragonite, depends on applied temperature and vary in the range, 8 < S a < 20. The precipitation was initiated by pouring 100 cm 3 of CaCl 2 solution into the same volume of Na 2 CO 3 solution. The initial concentrations of reactants were: c i (CaCl 2)= 0.010 mol dm-3 and c i (Na 2 CO 3)= 0.005 mol dm-3 , while the appropriate amount of MgCl 2 was added into the CaCl 2 solution. The concentration of MgCl 2 varied in the range, 0.010 mol dm-3 ≤ c(Mg 2+) i ≤ 0.100 mol dm-3. After the initial mixing of the reactants, the systems were tightly closed and agitated for 2.5 h at 40 C, 60 C or 80 C. The samples were gently agitated in thermostated orbital shaker in order to reduce the crystal attrition and secondary nucleation. Characterization of precipitates After completing the precipitation, the total volume of suspension was filtered through a 0.22 µm membrane filter, the precipitate was washed with small portions of water and dried at 105 C. The mineralogical composition of the dried samples was determined by means of infra red spectroscopy (FT-IR Bruker, Tensor II) using KBr pellets, and by X-ray powder diffraction (PANanalytical X'PertPRO, powder diffractometer equipped with a monochromator on the diffracted beam, using Cu K radiation (40 mA, 40 kV)). The morphology of the crystals was examined by scanning electron microscopy (FEG SEM Hitachi 6400). Data analyses The known total initial concentrations of CaCl 2 , Na 2 CO 3 and MgCl 2 were used for calculation of molar concentrations and activities of the relevant ionic species:

Acta Crystallographica Section A Foundations of Crystallography, 2011

docking techniques and molecular dynamics simulations. Modeling results indicate that positions C... more docking techniques and molecular dynamics simulations. Modeling results indicate that positions C7 and C10 affect the conformation of three key elements (the M-loop, S3 and H3) in the lateral interactions that modulate the contacts between adjacent protofilaments. Alternatively, the change in C2 slightly rearranges the ligand in the binding site, thus modifying the interaction of the ligand C7 position with the M-loop.

Acta Crystallographica Section A Foundations of Crystallography, 2007

CrystEngComm, 2015

This research shows that by tailoring the assembly of lecithin molecules it is possible to modula... more This research shows that by tailoring the assembly of lecithin molecules it is possible to modulate the texture, polymorphism, size and shape of calcium carbonate crystals.

Advanced healthcare materials, 2015

Doxorubicin (DOX)/CaCO3 single crystals act as pH responsive drug carrier. A biomimetic approach ... more Doxorubicin (DOX)/CaCO3 single crystals act as pH responsive drug carrier. A biomimetic approach demonstrates that calcite single crystals are able, during their growth in the presence of doxorubicin, to entrap drug molecules inside their lattice along specific crystallographic directions. Alterations in lattice dimensions and microstructural parameters are determined by means of high-resolution synchrotron powder diffraction measurements. Confocal microscopy confirms that doxorubicin is uniformly embedded in the crystal and is not simply adsorbed on the crystal surface. A slow release of DOX was obtained preferentially in the proximity of the crystals, targeting cancer cells.

Nature climate change, 2014

Anthropogenic CO2 is a major driver of current environmental change in most ecosystems(1), and th... more Anthropogenic CO2 is a major driver of current environmental change in most ecosystems(1), and the related ocean acidification (OA) is threatening marine biota(2). With increasing pCO2, calcification rates of several species decrease(3), although cases of up-regulation are observed(4). Here, we show that biological control over mineralization relates to species abundance along a natural pH gradient. As pCO2 increased, the mineralogy of a scleractinian coral (Balanophyllia europaea) and a mollusc (Vermetus triqueter) did not change. In contrast, two calcifying algae (Padina pavonica and Acetabularia acetabulum) reduced and changed mineralization with increasing pCO2, from aragonite to the less soluble calcium sulphates and whewellite, respectively. As pCO2 increased, the coral and mollusc abundance was severely reduced, with both species disappearing at pH < 7.8. Conversely, the two calcifying and a non-calcifying algae (Lobophora variegata) showed less severe or no reductions wit...

Marine Drugs, 2014

The squid pen (gladius) from the Loligo vulgaris was used for preparation of β-chitin materials c... more The squid pen (gladius) from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro-and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the β-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the β-chitin is modified, due to the intercalation of water molecules between β-chitin sheets. Potential applications of these β-chitin materials

Journal of Materials Chemistry, 1998

... Giuseppe Falini,a Simona Fermani,a Massimo Gazzanob and Alberto Ripamonti*a aDipartimento di ... more ... Giuseppe Falini,a Simona Fermani,a Massimo Gazzanob and Alberto Ripamonti*a aDipartimento di Chimica &#x27;G. Ciamician&#x27;, Universita&#x27; degli Studi, via ... Pap., 1917, 124; KE Chave, J. Geol., 1954, 62, 266; FT Mackenzie, WD Bischoff, FC Bishop, M. Loijens, J. Schoonmaker and R ...