FIG. 4.

Amino acid oxidation products and cross-links formed by peroxidase enzymes. Protein oxidative damage mediated by EPO-generated reactive brominating species (RBS), MPO-generated reactive chlorinating species (RCS), reactive nitrating species (RNS), tyrosyl radical (oY), transition metal ions (M2+) that form hydroxyl radical, may be identified by stable products formed by each pathway. All are tyrosine derivatives, except the nonphysiologic o-tyrosine and m-tyrosine that form from the oxidation of phenylalanine.