Pegg A E, Jacobs G
Biochem J. 1983 Aug 1;213(2):495-502. doi: 10.1042/bj2130495.
S-Adenosyl-L-methionine decarboxylases were purified from rat ventral prostate, yeast (Saccharomyces cerevisiae), slime mould (Physarum polycephalum) and bacteria (Escherichia coli) and tested for inhibition by a variety of nucleosides related to S-adenosylmethionine and by methyl- and ethyl-glyoxal bis(guanylhydrazone). Although the enzymes from these different sources are markedly different with respect to activation by cations, the inhibition by nucleosides was quite similar. Very little inhibition was seen when analogues of S-adenosylmethionine with a different base were tested or when the ribose ring was opened or the positive charge on the sulphur atom was not present. Some derivatives in which the amino acid portion of the molecule was altered were more potent inhibitors, but again there was little difference between the enzymes from different sources. 5'-(Dimethylsulphonio)-5'-deoxyadenosine and S-adenosyl-3-methylthiopropylamine were the most inhibitory substances and had similar Ki values, suggesting that the aminopropyl group does not contribute significantly to the binding. All of the S-adenosylmethionine decarboxylases were strongly competitively inhibited by methylglyoxal bis(guanylhydrazone) and even more powerfully by its ethyl analogue, although the putrescine-activated enzymes from prostate and yeast were more sensitive than the bacterial and slime-mould enzymes. All of the S-adenosylmethionine decarboxylases tested bound to a column of methylglyoxal bis(guanylhydrazone) linked to Sepharose and were not eluted by 0.5 M-NaCl, but could be released by 1 mM concentrations of the drug, providing a rapid and efficient method for their purification.
S-腺苷-L-甲硫氨酸脱羧酶从大鼠腹侧前列腺、酵母（酿酒酵母）、黏菌（多头绒泡菌）和细菌（大肠杆菌）中纯化出来，并测试了其对多种与S-腺苷甲硫氨酸相关的核苷以及甲基乙二醛双（脒腙）的抑制作用。尽管这些不同来源的酶在阳离子激活方面存在显著差异，但核苷的抑制作用却相当相似。当测试具有不同碱基的S-腺苷甲硫氨酸类似物、核糖环打开或硫原子上不存在正电荷时，几乎没有观察到抑制作用。一些分子中氨基酸部分发生改变的衍生物是更强效的抑制剂，但不同来源的酶之间同样差异不大。5'-（二甲基硫鎓）-5'-脱氧腺苷和S-腺苷-3-甲基硫丙胺是最具抑制性的物质，且具有相似的Ki值，这表明氨丙基对结合的贡献不大。所有的S-腺苷甲硫氨酸脱羧酶都受到甲基乙二醛双（脒腙）的强烈竞争性抑制，其乙基类似物的抑制作用更强，不过前列腺和酵母中由腐胺激活的酶比细菌和黏菌中的酶更敏感。所有测试的S-腺苷甲硫氨酸脱羧酶都能与连接到琼脂糖上的甲基乙二醛双（脒腙）柱结合，不能被0.5 M氯化钠洗脱，但可被1 mM浓度的该药物释放，这为其纯化提供了一种快速有效的方法。
