Isolation,purification and characterization of L-glutamate oxidase from Streptomyces sp.

The L-glutamate oxidase(GLOD) produced by Streptomyces sp.was purified by fraction precipitation by ammonium sulfate,HPLC desalination,ion exchange,Superdex G-200 Gel filtration chromatography and other steps.The electrophoresis purity was examined by SDS-PAGE,and the relative molecular weight of purified enzyme is 140ku.The properties of the L-glutamate oxidase were studied.The optimal temperature and pH value were 50℃ and 7.0,respectively.The enzyme was stable between 0℃～50℃ and within pH value 6.0～9.0.The Km value for hydrolyzation of L-glutamic acid by this enzyme was 2.1×10-4mol/L.Metal ions of K+,Na+ and Mg2+ had little effect on the activity of GLOD,but Hg2+,Cu2+ and Ag+ can inhibit the activity of the enzyme.