Protein Peroxidation: The Covalent Modification of Protein Induced Through Reactive Oxygen Species (ROS) and With Secondary By-products of Oxidative Stress.

Abstract

The abundance in biological system and high reaction rate constant are making the proteins as major targets for radicals and two-electron oxidants in biological systems. The multiple side-chain and backbone sites are susceptible for highly reactive radical damage. Less reactive species exhibit greater selectivity with reference to the residues targeted and their spatial location. Modified structure may result in the increased side-chain hydrophilicity, side-chain fragmentation and backbone fragmentation, aggregation through covalent cross-linking or hydrophobic interactions, unfolding of protein and altered conformation, altered interactions with biological partners and modified turnover. In the presence of oxygen, high yields of peroxyl radicals and peroxides of protein (through peroxidation) are formed. The peroxides of protein account for up to 70 % of the initial oxidant flux. The peroxides of protein deserve capability to oxidize both proteins and other target compounds. Key words:\xa0 Oxidation of amino acids; Hydroperoxide; Peroxidatio;, Peroxides