Carbon-Centered Radicals Can Transfer Hydrogen Atoms between Amino Add Side Chains

摘要

The nature and structure of radicals that can be formed in amino acids (AAs), peptides, and proteins have been extensively studied owing to their role in radiation, as well as in prebiotic chemistry and biochemistry. However, the discovery of the role of radicals in enzymatic catalysis has recently shed new light on the need for a better description of protein and AA radical reactivity. In these enzymes, tyrosyl, thiyl, and glycyl radicals are able to transfer hydrogen atoms, either directly or by a sequential electron and proton transfer. Nevertheless, the properties of radicals from 17 other AAs, and especially of carbon-centered (C~·) radicals that are involved in most protein oxidative degradations, are only now beginning to be described.