Aggregation of lysozyme and of poly(ethylene glycol)-modified lysozyme after adsorption to silica

摘要: Abstract Surface-induced aggregation is a common instability during protein storage, delivery and purification. This can lead to the formation of fibrils rich in intermolecular β-sheet structure. Techniques probe surface-clustering are limited. Here we use intrinsic fluorescence thioflavin T total internal reflection (TIRF) sampling geometry simultaneously monitor kinetics adsorption for chicken egg lysozyme on silica surface. We observe slow surface-induced process that continues well after have plateaued. The rate independent concentration solution. Consistent with clustering observed via fluorescence, infrared amide I band spectra also show 1.5-fold increase content upon adsorption. Tryptophan emission no evidence any tertiary structural change Furthermore, covalent modification single poly(ethylene glycol) (PEG) grafted chain does not inhibit surface, but second PEG graft significantly inhibits formation.