Abstract
The purpose of this study is to detect superoxide dismutase (SOD) in periodontopathic Bacteroides gingivalis. Superoxide anion (O2-) produced by NADP H-oxidase of white blood cell membrane, oxygendependent bactericidal reagent, is specifically antagonized by SOD.
Escherichia coli, facultative anaerobic bacterium, has two kinds of SOD (one contains manganase and another contains iron at their active site). Until recently, it was considered that strict anaerobic bacteria do not have SOD, but it is reported that strict anaerobic bacteria, for example Clostridium and Bacteroides possess SOD activity.
Bacteroides gingivalis was cultured in anaerobic condition, sonicated for 30min, and the portion of SOD activity was obtained by adding ammonium sulfate. The SOD activity was measured by cytochrome C method and by nitroblue tetrazolium (NBT) reducing activity in polyacrylamide gel electrophoresis (PAGE).
The results obtained were as follows;
1. Bacteroides gingivalis had significant SOD activity, and its enzymatic activity determined by cytochrome C method was 27units/mg protein.
2. The NBT reducing activity of Bacteroides gingivalis, located in polyacrylamide gel electrophoresis between the portion of supper-zinc SOD and the portion of SOD activity of Escherichia coli.
