Four-electron reduction of dioxygen by a multicopper oxidase, CueO, and roles of Asp112 and Glu506 located adjacent to the trinuclear copper center
スポンサーリンク
概要
- 論文の詳細を見る
The mechanism of the four-electron reduction of dioxygen by a multicopper oxidase, CueO, was studied based on reactions of single and double mutants with Cys500, a type I copper ligand, and the noncoordinating Asp112 and Glu506, which form hydrogen bonds with the trinuclear copper center directly and indirectly via a water molecule. The reaction of C500S containing a vacant type I copper center produced intermediate I in an EPR-silent peroxide-bound form. The formation of intermediate I from C500S/D112N was restricted due to a reduction in the affinity of the trinuclear copper center for dioxygen. The state of intermediate I was realized to be the resting form of C500S/E506Q and C500S of the truncated mutant Δα5-7CueO, in which the 50 amino acids covering the substrate-binding site were removed. Reactions of the recombinant CueO and E506Q afforded intermediate II, a fully oxidized form different from the resting one, with a very broad EPR signal, g < 2, detectable only at cryogenic temperatures and unsaturated with high power microwaves. The lifetime of intermediate II was prolonged by the mutation at Glu506 involved in the donation of protons. The structure of intermediates I and II and the mechanism of the four-electron reduction of dioxygen driven by Asp112 and Glu506 are discussed. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.
- American Society for Biochemistry and Molecular Biologyの論文
- 2009-05-22
American Society for Biochemistry and Molecular Biology | 論文
- Functions of chondroitin sulfate/dermatan sulfate chains in brain development: Critical roles of E and iE disaccharide units recognized by a single chain antibody GD3G7.
- Interaction between the N-terminal and middle regions is essential for the in vivo function of HSP90 molecular chaperone.
- Four-electron reduction of dioxygen by a multicopper oxidase, CueO, and roles of Asp112 and Glu506 located adjacent to the trinuclear copper center
- Intracellular Trafficking Pathway of Yeast Long-chain Base Kinase Lcb4, from Its Synthesis to Its Degradation
- Regulation of the transport and protein levels of the inositol phosphorylceramide mannosyltransferases Csg1 and Csh1 by the Ca2+ binding protein Csg2