Protein aggregation mechanism

Although ionic surfactants are often associated with denaturation of proteins [104], the nonionic surfactant polysorbate 80 has been included in several marketed formulations and serves to inhibit protein aggregation. The mechanism may be the greater tendency of the surfactant molecules to align themselves at the liquid/ air interface, excluding the protein from the interface and inhibiting surface denaturation. 

Chi, E.Y., Krishnan, S., Randolph, T.W., and Carpenter, J.F. 2003. Physical stability of proteins in aqueous solution mechanism and driving forces in nonnative protein aggregation. Pharmaceutical Research 20(9), 1325-1336. 

Protein aggregation is a hallmark of scrapie, and scrapie protein can be induced to aggregate in vitro into forms that are indistinguishable from pathological brain-derived fibrils. Prusiner proposed that prion disease involves a mechanism for autocatalytic conversion of a host... 

Many natural channels, particularly those for simple ions, form at the confluence of complex proteins. This mechanism has been simplified by the Gokel group which has prepared alkyl-terminated hexapeptides that contain a short proline containing peptide sequence, GGGPGGG, similar to that found in natural Cl -selective channels [14], These compounds give Cl- selectivity when anchored in phospholipid vesicles. It is assumed that channels form by supramolecular aggregation of the hexapeptides around the proline motif, shown in Fig. 5.6. Such a simple transport mechanism has yet to be seen in Nature but it would not be too surprising if one were to be found. 

After fermentation, the yeast cells were harvested and broken mechanically in a bead mill, and differential centrifugation was used to partition the cellular components into water-soluble and insoluble fractions. SDS-polyacrylamide gel electrophoresis in conjunction with Western blot analysis 36) revealed that the polyphenolic protein aggregated with the insoluble cellular protein. 

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