title: [Preliminary study on the rules of streptococcus mutans reactive oxygen species metabolism].
abstract: OBJECTIVE
  To study the rules of Streptococcus mutans reactive oxygen species metabolism and its enzymatic basis, and to investigate its significance intermediate to plaque microbial ecology.
  
  
  METHODS
  Electron spin trapping method was used to measure reactive oxygen species produced by Streptococcus mutans in the different incubation conditions, and evaluate the efficicay of NADH to hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system.
  
  
  RESULTS
  Electron spin resonance (ESR) spectrum of DMPO-O2- and DMPO-OH. and superoxide dismutase were obtained in Streptococcus mutans culture fluid, these spectrum were strengthened by exogenous sugar, and disappeared when methylene blue was added to culture fluid, but that spectrum was not significantly changed by NADH. ESR spectrum of hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system were significantly reduced or disappeared by NADH.
  
  
  CONCLUSIONS
  These results suggest that there are O2- and OH in Streptococcus mutans metabolism, and they may come mainly from the reaction catalyzed by NADH oxidase.
authors.affiliation: Department of Biochemistry, Beijing Institute of Basic Medical Sciences, Beijing 100850, China.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Wu
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D017382:Reactive Oxygen Species; D013295:Streptococcus mutans / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D017382:Reactive Oxygen Species; D013481:Superoxides; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases