HIGHLY SPECIFIC OXIDATIVE CROSS-LINKING OF PROTEINS MEDIATED BY A NICKEL-PEPTIDE COMPLEX

The Ni(II) complex of the tripeptide NH2-Gly-Gly-His-COOH is shown to mediate efficient protein-protein cross-linking in the presence of oxi dants such as oxone and monoperoxyphthalic acid. Only proteins that as sociate specifically in solution are cross-linked under these conditio ns. Preliminary probes of the mechanism of the reaction suggest that t he active intermediate may be a high-valent metal complex that attacks aromatic amino acids.