| Literature DB >> 17069757 |
Paolo Ascenzi1, Mario Milani, Paolo Visca.
Abstract
Mycobacterium leprae GlbO has been proposed to represent merging of both O(2) uptake/transport and scavenging of nitrogen reactive species. Peroxynitrite reacts with M. leprae GlbO(II)-NO leading to GlbO(III) via the GlbO(III)-NO species. The value of the second order rate constant for GlbO(III)-NO formation is >1x10(8)M(-1)s(-1) in the absence and presence of CO(2) (1.2x10(-3)M). The CO(2)-independent value of the first order rate constant for GlbO(III)-NO denitrosylation is (2.5+/-0.4)x10(1)s(-1). Furthermore, peroxynitrite reacts with GlbO(II)-O(2) leading to GlbO(III) via the GlbO(IV)O species. Values of the second order rate constant for GlbO(IV)O formation are (4.8+/-0.5)x10(4) and (6.3+/-0.7)x10(5)M(-1)s(-1) in the absence and presence of CO(2) (=1.2x10(-3)M), respectively. The value of the second order rate constant for the peroxynitrite-mediated GlbO(IV)O reduction (= (1.5+/-0.2)x10(4)M(-1)s(-1)) is CO(2)-independent. These data argue for a role of GlbO in the defense of M. leprae against nitrosative stress.Entities:
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Year: 2006 PMID: 17069757 DOI: 10.1016/j.bbrc.2006.10.060
Source DB: PubMed Journal: Biochem Biophys Res Commun ISSN: 0006-291X Impact factor: 3.575