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Publication Abstract from PubMed

The dinuclear copper enzyme tyrosinase activates O2 to form a (mu-eta2:eta2-peroxido)dicopper(II) species, which hydroxylates phenols to catechols. However, the exact mechanism of phenolase reaction in the catalytic site of tyrosinase is still under debate. We herein report the near atomic resolution X-ray crystal structures of the active tyrosinases with substrate L-tyrosine. At their catalytic sites, CuA moved largely toward L-tyrosine (CuA1 to CuA2), whose phenol oxygen directly coordinates to CuA2, involving the movement of CuB (CuB1 to CuB2). The crystal structures and spectroscopic analyses of the dioxygen-bound tyrosinases demonstrated that the peroxide ligand rotated, spontaneously weakening its O-O bond. Thus, the copper migration induced by the substrate-binding accompanied rearrangement of the bound peroxide species so as to facilitate one of the peroxide oxygen atoms to access to the phenol substrate's epsilon carbon atom.

Copper-oxygen Dynamics in Tyrosinase Mechanism.,Fujieda N, Umakoshi K, Ochi Y, Nishikawa Y, Yanagisawa S, Kubo M, Kurisu G, Itoh S Angew Chem Int Ed Engl. 2020 Apr 30. doi: 10.1002/anie.202004733. PMID:32356371^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.