Abstract
Mycobacterium leprae GlbO has been proposed to represent merging of both O2 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 >1 × 108 M-1 s-1 in the absence and presence of CO2 (1.2 × 10-3 M). The CO2-independent value of the first order rate constant for GlbO(III)-NO denitrosylation is (2.5 ± 0.4) × 101 s-1. Furthermore, peroxynitrite reacts with GlbO(II)-O2 leading to GlbO(III) via the GlbO(IV){double bond, long}O species. Values of the second order rate constant for GlbO(IV){double bond, long}O formation are (4.8 ± 0.5) × 104 and (6.3 ± 0.7) × 105 M-1 s-1 in the absence and presence of CO2 (=1.2 × 10-3 M), respectively. The value of the second order rate constant for the peroxynitrite-mediated GlbO(IV){double bond, long}O reduction (= (1.5 ± 0.2) × 104 M-1 s-1) is CO2-independent. These data argue for a role of GlbO in the defense of M. leprae against nitrosative stress.
Original language | English |
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Pages (from-to) | 528-533 |
Number of pages | 6 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 351 |
Issue number | 2 |
DOIs | |
Publication status | Published - Dec 15 2006 |
Keywords
- Carbon dioxide
- GlbO
- Mycobacterium leprae
- Peroxynitrite
- Scavenging of nitrogen reactive species
- Truncated hemoglobin
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology