2020/05/27 by Anasua Mukhopadhyay, Iliya D. Stoev, Mukhopadhyay, Anasua +7
Chemistry · Agricultural and Biological Sciences · Materials Science · #Surfactants and Colloidal Systems #Proteins in Food Systems #Pickering emulsions and particle stabilization
paper · pdf · doi:10.48550/arxiv.2005.13389
Prevention of protein aggregation and thus stabilization of proteins has\nlarge biological and biotechnological implications. Here, we show that\ninhibition of amyloid-like aggregates is possible in stoichiometric conjugates\nof polymer surfactant and bovine serum albumin (BSA) chosen as a model protein.\nWe investigate using a combination of Thioflavin-T fluorescence spectroscopy,\ndynamic light scattering and FTIR spectroscopy the aggregation behavior in\npolymer surfactant modified and unmodified (native) BSA solutions. The\nBSA-polymer surfactant conjugates are stable up to 5 days under aggregation\nconditions, while native BSA forms amyloid fibrillar structures. Further,\nDLS-based micro-rheology studies performed with heat-treated 100 to 200 \μM\nnative BSA aggregates provided understanding of the equilibrium elastic and\nviscous moduli over a very large frequency range, reaching MHz, which are\ninaccessible using bulk rheology. Our results indicate that after 6 days of\naggregation conditions, elastic moduli showed values between 1.2 to 3.6 Pa\ncorresponding to an entanglement length (\ξ) of 105 nm. Interestingly,\nheating 200 \μM native BSA solution at 65 degree C for 2 days in a plastic\nEppendorf resulted in self-standing films. These films exhibited strong\nThT-fluorescence intensity and a predominant beta-sheet secondary structure\nfrom the FTIR studies, suggesting that self-standing microstructure resulted\nfrom hierarchical self-assembly of amyloid fibrils.\n