Yamamoto H, Sumikawa K, Hada T, Higashino K, Yamamura Y
Clin Chim Acta. 1981 Apr 9;111(2-3):229-37. doi: 10.1016/0009-8981(81)90190-x.
gamma-Glutamyltransferase was solubilized from human hepatoma tissues by bromelain treatment, and some of its properties were compared with those of the normal adult liver enzyme. An electrophoretic study showed a slightly different mobility between the two enzymes before and after neuraminidase treatment. The hepatoma tissue enzyme was distinguished from the normal liver enzyme by decreased affinity to Con A. However, the enzymes from the two sources were found to be very similar or identical with respect to molecular weight, Michaelis constant, pH optimum, thermostability, effect of various L-amino acids as acceptors, behavior to divalent cations or ethylenediaminetetraacetate, inhibition by urea or sodium dodecyl sulfate, and immunological properties. These results suggest that the hepatoma tissue gamma-glutamyltransferase is largely due to altered glycosylation of this glycoprotein in hepatoma cells.
通过菠萝蛋白酶处理从人肝癌组织中溶解出γ-谷氨酰转移酶，并将其一些特性与正常成人肝脏酶的特性进行了比较。电泳研究表明，两种酶在神经氨酸酶处理前后的迁移率略有不同。肝癌组织酶与正常肝脏酶的区别在于对伴刀豆球蛋白A的亲和力降低。然而，发现来自两种来源的酶在分子量、米氏常数、最适pH值、热稳定性、各种L-氨基酸作为受体的作用、对二价阳离子或乙二胺四乙酸的反应、尿素或十二烷基硫酸钠的抑制作用以及免疫特性方面非常相似或相同。这些结果表明，肝癌组织中的γ-谷氨酰转移酶很大程度上是由于肝癌细胞中这种糖蛋白糖基化的改变。
