Study of thermal denaturation of oat globulin by ultraviolet and fluorescence spectrophotometry

Abstract

Thermal denaturation of dilute (<0.05%) oat globulin solutions at high ionic strength was studied by ultraviolet (UV) and fluorescence spectrophotometry. Ultraviolet spectra show a significant red shift of absorption maximum when the protein was heated at 110°C. Second-derivative and difference-derivative spectra suggest exposure of tryptophan and tyrosine residues in the heated samples. Fluorescence emission spectra show a significant blue shift, indicating protein unfolding. When 1% oat globulin was heat aggregated and fractionated into soluble and insoluble fractions, UV and fluorescence spectra indicate no marked protein unfolding in the soluble fraction but extensive denaturation in the insoluble aggregates. The soluble fraction had significantly higher surface hydrophobicity than the soluble fraction and the unheated protein.link_to_subscribed_fulltex