The two oxidized forms of the trinuclear Cu cluster in the multicopper oxidases and mechanism for the decay of the native intermediate.

ABSTRACT: Multicopper oxidases (MCOs) catalyze the 4e(-) reduction of O(2) to H(2)O. The reaction of the fully reduced enzyme with O(2) generates the native intermediate (NI), which undergoes a slow decay to the resting enzyme in the absence of substrate. NI is a fully oxidized form, but its spectral features are very different from those of the resting form (also fully oxidized), because the type 2 and the coupled-binuclear type 3 Cu centers in the O(2)-reducing trinuclear Cu cluster site are isolated in the resting enzyme, whereas these are all bridged by a micro(3)-oxo ligand in NI. Notably, the one azide-bound NI (NI(Az)) exhibits spectral features very similar to those of NI, in which the micro(3)-oxo ligand in NI has been replaced by a micro(3)-bridged azide. Comparison of the spectral feature

SUBMITTER: Yoon J 

PROVIDER: S-EPMC1959429 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature