Spread and adsorbed layers of protein fibrils at water -air interface.

The properties of adsorbed layers of protein fibrils differ significantly from the properties of fibril spread layers on an aqueous subphase. If the dependencies of the dynamic surface elasticity on surface pressure of Lysozyme (LYS) and β-lactoglobulin (BLG) aqueous dispersions proved to be close to the results for native protein solutions, LYS and BLG spread layers on the surface of 0.1 M NaCl solution exhibited the surface elasticity more than two times higher than the values for protein solutions with the same NaCl concentatration, presumably due to lower surface concentrations of hydrolysed peptides in the latter case. The properties of fibril spread and adsorbed layers and also their morphology, unlike the surface properties of protein solutions, depend noticeably on the ionic strength of the aqueous bulk phase. This dependence is stronger in case of LYS layers, which are also more prone to the formation of macroscopic and mesoscopic surface aggregates as compared with BLG layers.