Effects of oxidative damage in protein structure and function.
|(i) Cleavage of peptide bonds|
|(ii) Direct reaction of proteins with ROS can lead to formation of protein derivatives or peptide fragments possessing highly reactive carbonyl groups (ketones, aldehydes)|
|(iii) Formation of intra- or interprotein cross-linked derivatives that can lead to the formation of aggregates by (a) direct interaction of two carbon-centered radicals; (b) interaction of two tyrosine radicals; (c) oxidation of cysteine sulfhydryl groups; (d) interactions of the carbonyl groups of oxidized proteins with the primary amino groups of lysine residues in the same or a different protein; (e) by noncovalent interactions such as hydrophobic and electrostatic interactions between oxidized residues|
|(iv) Partial unfolding or denaturation with a concomitant increase in surface hydrophobicity|
|(v) Loss of function (e.g., enzyme activity)|