%0 Journal Article %1 cardinale_determinants_2005 %A Cardinale, Jean A %A Clark, Virginia L %D 2005 %J Molecular Microbiology %K Anaerobiosis, Concentration, Female, Gonorrhea, Humans, Neisseria Nitric Nitrite Nitrites, Nitrous Oxide, Oxidoreductases, Reductases, Triazenes gonorrhoeae, {Hydrogen-Ion} %N 1 %P 177--88 %R MMI4807 %T Determinants of nitric oxide steady-state levels during anaerobic respiration by Neisseria gonorrhoeae %U http://www.ncbi.nlm.nih.gov/pubmed/16164557 %V 58 %X Nitric oxide (NO) is an important host defence molecule that varies its immune stimulatory effects depending on the concentrations at which it is produced, with low concentrations (\textless 1 microM) promoting an anti-inflammatory host response while higher concentrations (\textgreater1 microM) lead to inflammatory responses. Neisseria gonorrhoeae grows anaerobically by anaerobic respiration using nitrite reductase (Nir) to convert nitrite to NO and nitric oxide reductase (Nor) to convert NO to nitrous oxide. As N. gonorrhoeae can both produce and degrade NO, we have begun a study of NO metabolism in this bacterium to understand how gonococcal manipulation of NO concentration may influence the inflammatory response during infection. N. gonorrhoeae has an apparent Nir Km of 33 microM nitrite and an apparent Nor Km of 1.2 microM NO. The maximum specific activities for Nir and Nor were 135 nmoles nitrite reduced per minute per OD600 (pH 6.7) and 270 nmoles NO reduced per minute per OD600 (pH 7.5) respectively. N. gonorrhoeae established a steady-state concentration of NO after nitrite addition that was dependent on the nitrite concentration until saturation at 1 mM nitrite. The NO steady-state level decreased as pH increased, and the ratio of activities of Nir and Nor correlated to the NO steady-state level. When the NO donor DETA/NO was used to simulate host NO production, N. gonorrhoeae also established a NO steady-state level. The concentration of NO at steady state was found to be a function of the concentration of NO generated by DETA/NO, with N. gonorrhoeae reducing the NO from proinflammatory (\textgreater1 microM) to anti-inflammatory (approximately 100 nM) concentrations. The implications of the ability of N. gonorrhoeae to maintain an anti-inflammatory NO concentration is discussed in relation to asymptomatic infection in women.

@article{cardinale_determinants_2005, abstract = {Nitric oxide {(NO)} is an important host defence molecule that varies its immune stimulatory effects depending on the concentrations at which it is produced, with low concentrations ({\textless} 1 {microM)} promoting an anti-inflammatory host response while higher concentrations ({\textgreater}1 {microM)} lead to inflammatory responses. Neisseria gonorrhoeae grows anaerobically by anaerobic respiration using nitrite reductase {(Nir)} to convert nitrite to {NO} and nitric oxide reductase {(Nor)} to convert {NO} to nitrous oxide. As N. gonorrhoeae can both produce and degrade {NO,} we have begun a study of {NO} metabolism in this bacterium to understand how gonococcal manipulation of {NO} concentration may influence the inflammatory response during infection. N. gonorrhoeae has an apparent Nir Km of 33 {microM} nitrite and an apparent Nor Km of 1.2 {microM} {NO.} The maximum specific activities for Nir and Nor were 135 nmoles nitrite reduced per minute per {OD600} {(pH} 6.7) and 270 nmoles {NO} reduced per minute per {OD600} {(pH} 7.5) respectively. N. gonorrhoeae established a steady-state concentration of {NO} after nitrite addition that was dependent on the nitrite concentration until saturation at 1 {mM} nitrite. The {NO} steady-state level decreased as {pH} increased, and the ratio of activities of Nir and Nor correlated to the {NO} steady-state level. When the {NO} donor {DETA/NO} was used to simulate host {NO} production, N. gonorrhoeae also established a {NO} steady-state level. The concentration of {NO} at steady state was found to be a function of the concentration of {NO} generated by {DETA/NO,} with N. gonorrhoeae reducing the {NO} from proinflammatory ({\textgreater}1 {microM)} to anti-inflammatory (approximately 100 {nM)} concentrations. The implications of the ability of N. gonorrhoeae to maintain an anti-inflammatory {NO} concentration is discussed in relation to asymptomatic infection in women.}, added-at = {2011-03-11T10:05:34.000+0100}, author = {Cardinale, Jean A and Clark, Virginia L}, biburl = {https://www.bibsonomy.org/bibtex/27bf8dc0d44f2dc38ca813de21afc8099/jelias}, doi = {MMI4807}, interhash = {771e5367e1c9f052efe850dec763a01a}, intrahash = {7bf8dc0d44f2dc38ca813de21afc8099}, issn = {{0950-382X}}, journal = {Molecular Microbiology}, keywords = {Anaerobiosis, Concentration, Female, Gonorrhea, Humans, Neisseria Nitric Nitrite Nitrites, Nitrous Oxide, Oxidoreductases, Reductases, Triazenes gonorrhoeae, {Hydrogen-Ion}}, month = oct, note = {{PMID:} 16164557}, number = 1, pages = {177--88}, timestamp = {2011-03-11T10:05:49.000+0100}, title = {Determinants of nitric oxide steady-state levels during anaerobic respiration by Neisseria gonorrhoeae}, url = {http://www.ncbi.nlm.nih.gov/pubmed/16164557}, volume = 58, year = 2005 }