Journal
BIOCHEMICAL JOURNAL
Volume 433, Issue -, Pages 383-391Publisher
PORTLAND PRESS LTD
DOI: 10.1042/BJ20100960
Keywords
cytochrome b(5); mitochondrial amidoxime reducing component (mARC); benzamidoxime; Mo cofactor sulfurase C-terminal-domain-containing (MOSC); nitric oxide; N-omega-hydroxy-L-arginine (NOHA)
Categories
Funding
- Deutsche Forschungsgemeinschaft (DFG) [CI 56/9-1, ME 1266/24-1]
Ask authors/readers for more resources
NOSs (nitric oxide synthases) catalyse the oxidation of L-arginine to L-citrulline and nitric oxide via the intermediate NOHA (N-omega-hydroxy-L-arginine). This intermediate is rapidly converted further, but to a small extent can also be liberated from the active site of NOSs and act as a transportable precursor of nitric oxide or potent physiological inhibitor of arginases. Thus its formation is of enormous importance for the nitric-oxide-generating system. It has also been shown that NOHA is reduced by microsomes and mitochondria to L-arginine. In the present study, we show for the first time that both human isoforms of the newly identified mARC (mitochondrial amidoxime reducing component) enhance the rate of reduction of NOHA, in the presence of NADH cytochrome b(5) reductase and cytochrome b(5), by more than 500-fold. Consequently, these results provide the first hints that mARC might be involved in mitochondria] NOHA reduction and could be of physiological significance in affecting endogenous nitric oxide levels. Possibly, this reduction represents another regulative mechanism in the complex regulation of nitric oxide biosynthesis, considering a mitochondria! NOS has been identified. Moreover, this reduction is not restricted to NOHA since the analogous arginase inhibitor NHAM (N-omega-hydroxy-N-delta-methyl-L-arginine) is also reduced by this system.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available