Kang H, Cho Y D
Department of Biochemistry, College of Science, Yonsei University, Seoul, Korea.
Biochem Biophys Res Commun. 1996 Jun 14;223(2):288-92. doi: 10.1006/bbrc.1996.0886.
Transglutaminase was purified to homogeneity from leaves of soybean (Glycine max). The molecular weight of the enzyme estimated by gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis was 80,000 daltons. This purified enzyme catalyzed the incorporation of [14C]-putrescine into N,N'-dimethylcasein as a protein substrate. With N,N'-dimethylcasein, the Km values for putrescine, spermidine and spermine were 109, 42 and 69 microM, respectively. The optimum pH and temperature for the enzyme reaction were 7.6 and 37 degrees C. Ca2+ was not an absolute requirement for enzyme activity unlike animal transglutaminases. The enzyme was activated by dithiothreitol, but inhibited by GTP. With molecular weight of this enzyme, this inhibition of enzyme activity by GTP indicates that this enzyme is very similar to known tissue transglutaminases in animals.
从大豆（Glycine max）叶片中纯化出了均一的转谷氨酰胺酶。通过凝胶过滤和十二烷基硫酸钠聚丙烯酰胺凝胶电泳估算，该酶的分子量为80,000道尔顿。这种纯化后的酶催化将[14C] - 腐胺掺入作为蛋白质底物的N，N'-二甲基酪蛋白中。对于N，N'-二甲基酪蛋白，腐胺、亚精胺和精胺的Km值分别为109、42和69微摩尔。酶反应的最适pH和温度分别为7.6和37℃。与动物转谷氨酰胺酶不同，Ca2+不是酶活性的绝对必需条件。该酶被二硫苏糖醇激活，但被GTP抑制。鉴于该酶的分子量，GTP对酶活性的这种抑制表明该酶与动物中已知的组织转谷氨酰胺酶非常相似。
