海洋细菌Bacillus sp.2-羰基还原酶的纯化和性质

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

从一株海洋细菌Bacillussp .中通过硫酸铵分级盐析、QSepharoseFF阴离子交换层析、Hydroxyapatite柱层析和SephadexG 1 0 0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 羰基醛还原酶。以粗酶液作起始 ,所获样品纯度提高 1 41 4倍 ,活力回收率 1 1 4%。 2 羰基醛化合物对该酶是特异性很好的底物 ,该酶对 3 脱氧葡糖醛酮的Km为 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。

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℃ and pH 5.0 ～8.0.EDTA,β\|mercaptoethanol and dithiothreitol enhanced the enzyme activity.On the other hand,the enzyme activity was partially lost by idoacetic acid or N\|ethylmaleimide.