obsolete peptide cross-linking via 4'-(L-tryptophan)-L-tryptophyl quinone (obsolete GO:0018069)
OBSOLETE. The cross-linking of a tryptophan residue to tryptophyl quinone to form 4'-(L-tryptophan)-L-tryptophyl quinone, a cofactor found at the active site of methylamine dehydrogenase.