Self-Assembly of Synthetic and Biological Polymeric Systems of ...

equire a highly organized and unstable nucleus, with a progressive increase of the β-
sheet (up to 26%) and an unordered conformation at the expense of the α-helical
conformation.
V. The fibrils obtained show a curly morphology and differ in length. Besides,
suprafibrillar assemblies (spherulites and fibrillar gels) formed by the protein human
serum albumin under different solution conditions.
VI. Upon incubation at 65 0 C at both acidic (pH 2.5) and physiological (pH 7.4) pH in the
presence of different amounts of added electrolyte, suprafibrillar assemblies,
spherulites and fibrillar gels, are formed under different solution conditions. Fibrillar
gels are formed through intermolecular nonspecific association of amyloid fibrils.
Meanwhile, at a pH close to the isoelectric point of HSA (pH 5.5), particulate gels were
observed as a consequence of a faster protein aggregation, which does not allow the
necessary structural reorganization to enable the formation of more ordered
structures.
VII. Within spherulites, fibrils display a radial arrangement around a disorganized protein
core with sizes of several micrometers, as revealed by POM and confocal microscopy.
VIII. Protein structure destabilization and subsequent aggregation (into amorphous or well-
defined structured aggregates) were conditioned by the experimental pH,
temperatures, and solvent polarity.
IX. Ethanol regulated the hydrogen bonding extension, the attractive hydrophobic
interactions, and the protein accessible surface area which, in turn, give rise to
intermediate structural states prone to form aggregate.
X. The HSA aggregation rate at physiological condition is faster than under acidic one
owing to the pre-existing structural differences of the protein molecules in solution
and to changes in the nature and strength of intermolecular interaction upon
incubation.
XI. Ethanol promoted an α-helix to β-sheet conformational transition at intermediate
alcohol concentrations, whereas at low and high ethanol contents α-helix prevailed as
the predominant structure at room temperature and physiological pH.
XII. Electrostatic and hydrophobic interactions are important to control stacking of β-
sheets favouring the formation of amyloid-like fibrils at physiological pH and high
temperature.
3. - On the metal and magnetic nanowires :
I. We report a method to obtain metallic Au nanowires by using Lys protein fibrils as
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