海洋细菌Bacillus sp.2—羧基还原酶的纯化和性质

从一株海洋细菌Bacillus sp，中通过硫酸铵分级盐析，Q Sepharose FF阴离子交换层析，Hydroxyapatite柱层析和Sephadex G-100凝胶过滤，分离纯化出一种3－脱氧]葡糖醛酮代谢酶，定性为2－羧基醛还原酶，以粗酶液作起始，所获样品纯度提高141．4倍，活力回收率11．4％，2－羧基醛化合物对酶是特异性很好的底物，该酶对3－脱氧葡糖醛酮的Km和2.5mmol/L，分子量约为33kD，反应最适pH为6．2，在pH5．0－8．0,温度30℃以下酶活保持稳定，适量的ED－TA，巯基乙醇或二硫苏糖醇能提高酶的活性，碘乙酸，N-乙基顺丁烯二酰亚胺均造成酶部分失活。

PURIFICATION AND CHARACTERIZATION OF 2-CARBONYL REDUCTASE FROM MARINE BACTERIA BACILLUS SP.

ANADPH-dependent 2-Oxoaldehyde reductase was isolated and purified from a marine bacteria Bacillus sp. The purification procedure involved ammonium sulfate fractionation and Q Sepharose FF, Hydroxyapatite, Sephadex G-100 column chromatographies. The specific activity of the purified enzyme was increased by 141.1 folds over crude extract and the recovery yield was 11.4%. 2-Oxoaldehyde compounds were found to be speciall good substrates. The optimum pH of the enzyme activity was 6.2-6.6. The Km coefficient for 3-deoxyglucosone was 2.5 mmol/L. The molecular weight of the enzyme was estimated to be 33 kD The enzyme activity is stable below 30 degrees C and pH 5.0-8.0. EDTA, beta-mercaptoethanol and dithiothreitol enhanced the enzyme activity. On the other hand, the enzyme activity was partially lost by idoacetic acid or N-ethylmaleimide.