Effect of protein oxidation on the conformational properties of peanut protein isolate

Abstract

Peanut protein isolate (PPI) was oxidized by peroxyl radicals derived from 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH), and the conformational properties of oxidized PPI were investigated. Oxidation of PPI resulted in gradual carbonyl generation and free sulfydryl group degradation. The analysis of the maximum emission wavelength indicated change in the tertiary conformation of PPI after oxidation. Lower level oxidation could generate soluble protein aggregates with more flexible structure, while higher level oxidation would induce the formation of insoluble aggregates. Result from dynamic light scattering (DLS) and protein solubility showed that protein aggregation was correlated with protein surface hydrophobicity, indicating that protein oxidation and heat treatment could induce protein aggregation, leading to PPI conformational changes. © 2013 Lin Ye et al.