Chapter 4 - Chemical bases and biological relevance of protein oxidation

Abstract

This chapter discusses the chemistry and the patho-physiological relevance of biologically irreversible protein oxidation. It also discusses the chemistry of protein oxidation and presents examples and figures to explain tryptophan oxidation, tyrosine oxidation, oxidation of aliphatic amino acids and the peptide bond, protein oxidation chain reaction, hypochlorous acid mediated oxidation of dipeptides, and oxidation of other amino acids. There are several major areas that are the subjects of the review concerning protein oxidation and its biological relevance—(1) oxidative stress, protein oxidation, and aging, (2) protein oxidation in pathological conditions and various diseases, (3) the role of protein oxidation in the process of protein inactivation and degradation, (4) exercise, immobilization, and protein oxidation, and (5) plasma protein oxidation and modification because of exposure to cigarette smoke. The chapter discusses the role of protein oxidation in the processes of protein inactivation and degradation. With strenuous exercise, there is a marked elevation of oxidative stress to muscles. A wide variety of chemical protein modifications occur during protein oxidation. The modification of a protein by either a direct oxidation of a specific amino acid or cleavage of the protein backbone might result in impaired biological activity and changes in the secondary and tertiary structures of the protein. The oxidative stress in proteins results in faulty-protein accumulation in the organism's cells, tissues, and body fluid.