NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.50A [2011] >
IJC-A Vol.50A(03-04) [March-April 2011] >


Title: Probing dioxygen activation mechanisms in heme-containing enzymes by heme models
Authors: Liu, Jin-Gang
Naruta, Yoshinori
Keywords: Bioinorganic chemistry
Cytochrome c oxidase
Heme proteins
Enzyme models
Dioxygen activation
Issue Date: Mar-2011
Publisher: NISCAIR-CSIR, India
Abstract: In this mini-review, we summarize our recent synthetic model studies on the mechanism of dioxygen reduction reaction involved in cytochrome c oxidase (CcO), as well as on the dioxygen binding and activation associated with general heme-containing enzymes. A series of heme/copper dinuclear complexes bearing a cross-linked His-Tyr mimic have been designed and synthesized as synthetic models of the active site of CcO, focusing on the possible role(s) of the cross-linked His-Tyr-CuB moiety. The spectroscopic evidences from the oxygenation reaction of these model compounds demonstrate that the role(s) of the cross-linked His-Tyr moiety is more likely to be structural and a proton mediator rather than acting as the fourth electron donor in the dioxygen reduction process. It also implies that after one-electron reduction of the oxyheme unit in CcO under physiological conditions, O-O bond cleavage could occur through a FeIII-OOH rather than a peroxo FeIII-(O22-)-CuII species. In addition, as key intermediates involved in the catalytic cycles of heme-containing enzymes, the low-spin end-on ferric-peroxo and ferric-hydroperoxo intermediates have been successfully captured and spectroscopically characterized in solution for the first time by using of delicate designed heme models. The results suggest the crucial role of the axial imidazole ligation to heme for O2 activation
Page(s): 363-373
CC License:  CC Attribution-Noncommercial-No Derivative Works 2.5 India
ISSN: 0975-0975(Online); 0376-4710(Print)
Source:IJC-A Vol.50A(03-04) [March-April 2011]

Files in This Item:

File Description SizeFormat
IJCA 50A(03-04) 363-373.pdf606.76 kBAdobe PDFView/Open
 Current Page Visits: 1022 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2012 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 606123 since 06-Feb-2009  Last updated on 21-Oct-2014Webmaster: nopr@niscair.res.in