Yang Y G, Cho Y D
Department of Biochemistry, College of Science, Yonsei University, Seoul, Korea.
Biochem Biophys Res Commun. 1991 Dec 31;181(3):1181-6. doi: 10.1016/0006-291x(91)92063-p.
S-Adenosylmethionine decarboxylase (EC 4.1.1.19) was purified to homogeneity from the cytosol of soybean (Glycine max) axes by ammonium sulfate fractionation, DEAE-Sepharose and methylglyoxalbis(guanylhydrazone)-Sepharose 6B chromatographies. The enzyme was free from diamine oxidase activity. The molecular weight of the enzyme estimated by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis was 66,000. The Km value for S-adenosylmethionine was 0.26 mM. The optimum pH and temperature were 7.5 and 40 degrees C. Neither putrescine nor Mg2+ affected the enzyme activity, but the enzyme was inhibited by spermidine, spermine, methylglyoxalbis(guanylhydrazone), sodium borohydride and phenylhydrazine. Agmatine was a novel inhibitor which inhibited S-adenosylmethionine decarboxylase and arginine decarboxylase, preventing the accumulation of decarboxylated S-adenosylmethionine and putrescine, respectively.
通过硫酸铵分级沉淀、DEAE-琼脂糖和甲基乙二醛双（胍腙）-琼脂糖6B层析从大豆（Glycine max）胚轴的胞质溶胶中纯化出S-腺苷甲硫氨酸脱羧酶（EC 4.1.1.19）至均一。该酶无二胺氧化酶活性。通过凝胶过滤和十二烷基硫酸钠聚丙烯酰胺凝胶电泳估计该酶的分子量为66,000。S-腺苷甲硫氨酸的Km值为0.26 mM。最适pH和温度分别为7.5和40℃。腐胺和Mg2+均不影响该酶活性，但该酶受到亚精胺、精胺、甲基乙二醛双（胍腙）、硼氢化钠和苯肼的抑制。胍丁胺是一种新型抑制剂，它分别抑制S-腺苷甲硫氨酸脱羧酶和精氨酸脱羧酶，从而阻止脱羧化S-腺苷甲硫氨酸和腐胺的积累。
