Effect of (-)-epigallocatechin gallate on the fibrillation of human serum albumin.

Human serum albumin (HSA), the most abundant plasma protein in the human body is known to form fibrils under partial denaturing conditions. Natural polyphenols are known to interact with HSA and some polyphenols have been shown to be potent inhibitors of amyloid fibrillation. (-)-Epigallocatechin gallate (EGCG), the major component of green tea is known to inhibit amyloid fibrillation. In this report, we have investigated the effect of EGCG on native HSA as well as on the fibrillation process of HSA from amide III band analysis of their respective visible Raman spectra. The differential role of the tryptophan (Trp214) residue present in domain II of HSA in the absence and presence of EGCG has been pointed out using fluorescence anisotropy and visible Raman spectroscopy.