兔肝脏S-腺苷甲硫氨酸脱羧酶的性质：某些腙类化合物对其活性的影响。

Properties of S-adenosylmethionine decarboxylase from rabbit liver: effects of some hydrazone compounds on its activity.

作者信息

Balaña-Fouce R, Ordoñez-Escudero D, Sanz-Sánchez F, Garrido-Pertierra A

出版信息

Comp Biochem Physiol B. 1986;83(1):221-5. doi: 10.1016/0305-0491(86)90356-1.

Abstract

S-Adenosylmethionine decarboxylase (EC 4.1.1.50) has been partially purified from rabbit liver by ammonium sulphate fractionation and gel filtration and anion exchange chromatographies. Sodium dodecylsulphate-polyacrylamide disc gel electrophoresis analysis showed an approximate dimeric subunit mol. wt of 34,000. The enzyme showed a pH optimum at 7.5 (in phosphate buffer) and did not require bivalent cations for catalysis. The enzyme showed sigmoid kinetics to S-adenosylmethionine with a Hill coefficient of 1.7, which became michaelian with Km 70 microM in the presence of 2.5 mM putrescine. Methylglyoxal bis(guanylhydrazone) was an effective inhibitor of the enzyme, but phenylated derivatives of this compound as phenylglyoxal bis(guanylhydrazone) and diphenylglyoxal bis-(guanylhydrazone) inhibited less well.

摘要

S-腺苷甲硫氨酸脱羧酶（EC 4.1.1.50）已通过硫酸铵分级分离、凝胶过滤和阴离子交换色谱法从兔肝中部分纯化。十二烷基硫酸钠-聚丙烯酰胺圆盘凝胶电泳分析显示，其亚基分子量约为34,000，呈二聚体形式。该酶在pH 7.5（磷酸盐缓冲液中）表现出最佳活性，催化反应不需要二价阳离子。该酶对S-腺苷甲硫氨酸呈现S形动力学，希尔系数为1.7，在2.5 mM腐胺存在下，其动力学变为米氏动力学，Km为70 microM。甲基乙二醛双（脒腙）是该酶的有效抑制剂，但该化合物的苯基化衍生物，如苯乙二醛双（脒腙）和二苯乙二醛双（脒腙）的抑制效果较差。