Cyclodecapeptides to mimic the radical site of tyrosyl-containing proteins

Abstract

Tyrosyl radicals are involved in many biologically important processes. The development of model compounds to mimic radical enzyme active sites, such as galactose oxidase (GO), has widely contributed to an enhanced understanding of their spectral properties, structural attributes and even reactivity. An emerging approach towards the synthesis of such active site mimetics is the use of peptidic ligands. The potential of cyclodecapeptides to bear phenoxyl radicals has been evaluated through three compounds. LH4 2+ is a cyclodecapetide containing two histidine residues (mimicking His496 and His581 of GO) and two tyrosine residues (mimicking Tyr495 and the Tyr272· radical of GO). LtBuH4 2+ and L..