螺旋藻氢酶的纯化与生化特性

PURIFICATION AND PROPERTIES OF HYDROGENASE FROM SPIRULINA PLATENSIS

  • 摘要: 本研究用DE-52、SephadexG-75、SephadexG-100柱层析从螺旋藻分离纯化得到比活性提高200倍的氢酶,回收率为14%。凝胶柱层析和SDS-PAGE显示一条带,其分子量为56kd。氨基酸分析结果表明酸性氨基酸比例较大,等电聚焦测定结果证明其等电点为pH4.2。吸收光谱结果显示氢酶是铁硫蛋白。甲基紫晶(MV)是氢酶催化放氢的最佳电子供体,其Km(MV)为0.31mmol/L,最适pH值为7.5-8.0。

     

    Abstract: A hydrogenase has been purified by DE-52(1), Sephadex G-75, DE-52(2) and Sephadex G-100 from Spirulina platensis, showing one band on SDS-PAGE. Overall purification of about 200-fold was achieved with 14% recovery of enzyme activity.The average molecular weight of hydrogenase was 56kd identified by SDS-PAGE.The isoelectric point determined by isoelectric focusing electrophoresis was pH4.2. Analysis of amino acid composition indicated that hydrogenase consists of 456 amino acid residues, being rich in aspartic acid and glutamic acid. It was an iron-sulfer protein identified by absorption spectrum. The enzyme was able to catalyze hydrogen evolution in the presence of MV reduced by dithionite. The Km (MV) of hydrogenase was 0.31mmol/L. Its optimum pH was 7.5-8.0.

     

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