Carbon monoxide dehydrogenase in mycobacteria possesses a nitric oxide dehydrogenase activity.
CO dehydrogenase (CO-DH) catalyzes the oxidation of CO to CO(2) in carboxydobacteria. Cell-free extracts prepared from several mycobacteria, including Mycobacterium tuberculosis H37Ra, showed NO dehydrogenase (NO-DH) activity in a reaction mixture containing sodium nitroprusside (SNP) as the source of NO. The association of the NO-DH activity with CO-DH was revealed by activity staining and confirmed by enzyme assay with purified CO-DH from Mycobacterium sp. strain JC1, a carboxydotrophic mycobacterium. SNP stimulated the production of CO-DH with a coincidental increase in NO-DH activity in the bacterium, further supporting this association and implying the existence of a possible SNP-induced CO-DH gene expression. The addition of purified CO-DH to cultures of Escherichia coli revealed that the enzyme protected E. coli from SNP-induced killing in a dose-dependant way. The present results indicate that mycobacterial CO-DH also acts as a NO-DH, which may function in the protection of mycobacterial pathogens from nitrosative stress during infection.
Park
Sae Woong
SW
Department of Biology, Yonsei University, Seoul 120-749, Republic of Korea.
Song
Taeksun
T
Kim
Seo Young
SY
Kim
Eungbin
E
Oh
Jeong-Il
JI
Eom
Chi-Yong
CY
Kim
Young Min
YM
D000445:Aldehyde Oxidoreductases / Q000378:metabolism* / Q000494:pharmacology; D002384:Catalysis; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D050296:Microbial Viability / Q000187:drug effects; D009097:Multienzyme Complexes / Q000378:metabolism* / Q000494:pharmacology; D009161:Mycobacterium / Q000201:enzymology*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism / Q000494:pharmacology; D009599:Nitroprusside / Q000378:metabolism / Q000494:pharmacology; D010088:Oxidoreductases / Q000378:metabolism*; D013997:Time Factors
D009097:Multienzyme Complexes; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D010088:Oxidoreductases; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase