Purification and characterization of a sarcosine oxidase from Bacillus sp. BSD-8 / 生物工程学报

ABSTRACT

We purified a sarcosine oxidase from Bacillus sp. strain BSD-8 isolated from soil. We purified the enzyme by ammonium sulfate precipitation, DEAE-cellulose, Toyopearl hydrophobic and Sephadex G-75 molecular sieve chromatography and characterized the purified sarcosine oxidase. This sarcosine oxidase was a flavin enzyme containing a noncovalently bound flavin with the subunit molecular mass of 51 kDa. The optimal temperature for this enzyme was 60 degrees C and it showed its highest activity at pH 8.5. It was stable in the pH range of 8.0-10.0 and at the temperature of 60 degrees C. Estimated by Lineveaver-Burk plots, the K(m) of the enzyme was 3.1 mmol/L. Ag+, Hg2+, SDS and Tween 80 dramatically inhibted the enzyme activity, whereas Tween 20 and Triton X-100 had no effect on enzyme activity. The thermostability of this enzyme was better than reported sarcosine oxidases, and it could be applied in enzymatic measuring of creatinine.