Im Y S, Chiang P K, Cantoni G L
J Biol Chem. 1979 Nov 10;254(21):11047-50.
Guanidoacetate methyltransferase has been purified about 140-fold from pig liver. Polyacrylamide gel electrophoresis of the purified enzyme showed four protein bands, each of which is associated with guanidoacetate methyltransferase activity. During gel electrophoresis at pH 3 in 8 M urea, guanidoacetate methyltransferase migrated as a single component. The molecular weight of the purified guanidoacetate methyltransferase was estimated to be 31,000 by sodium dodecyl sulfate-gel electrophoresis, which also showed only one protein component with guanidoacetate methyltransferase activity. This molecular weight is in agreement with that estimated by Sephadex G-75 chromatography. Guanidoacetate methyltransferase is inhibited by adenosylhomocysteine, 3-deazaadenosylhomocysteine, and sinefungin with Ki values of 16 microM, 39 microM, and 18 microM, respectively.
胍乙酸甲基转移酶已从猪肝中纯化出来，纯化倍数约为140倍。纯化后的酶经聚丙烯酰胺凝胶电泳显示有四条蛋白带，每条带都与胍乙酸甲基转移酶活性相关。在pH 3的8 M尿素中进行凝胶电泳时，胍乙酸甲基转移酶以单一成分迁移。通过十二烷基硫酸钠-凝胶电泳估计纯化后的胍乙酸甲基转移酶分子量为31,000，该电泳也仅显示一种具有胍乙酸甲基转移酶活性的蛋白成分。此分子量与通过葡聚糖凝胶G-75色谱法估计的分子量一致。腺苷同型半胱氨酸、3-脱氮腺苷同型半胱氨酸和杀稻瘟菌素可抑制胍乙酸甲基转移酶，其抑制常数（Ki）值分别为16 microM、39 microM和18 microM。
