Characterization of Oligomeric Species on the Aggregation Pathway of Human Lysozyme

摘要: Abstract The aggregation process of wild-type human lysozyme at pH 3.0 and 60 °C has been analyzed by characterizing a series distinct species formed on the pathway, specifically amyloidogenic monomeric precursor protein, oligomeric soluble prefibrillar aggregates, mature fibrils. Particular attention focused analysis structural properties species, since recent studies have shown that oligomers prior to appearance amyloid fibrils are toxic cells. Here, range techniques including binding fluorescent probes such as thioflavin T 1-anilino-naphthalene-8-sulfonate, Fourier transform infrared spectroscopy, controlled proteolysis. Oligomers were isolated after 5 days incubation protein appear spherical particles with diameter 8–17 nm when observed transmission electron microscopy. Unlike solvent-exposed hydrophobic patches able bind probe 1-anilino-naphthalene-8-sulfonate. spectroscopy spectra indicative misfolded compared lysozyme, prevalence random structure but significant elements β-sheet is characteristic Moreover, aggregates found be more susceptible proteolysis pepsin than both fibrils, indicating further their less organized structure. In summary, this study shows locally unfolded present low concentration during initial phases aggregation. nonnative conformational features molecules which they composed likely factors confer them ability interact inappropriately variety cellular components membranes.