Kobata A, Yamashita K
Gan No Rinsho. 1984 May;30(6 Suppl):545-51.
Comparative study by using hydrazinolysis has revealed that the carbohydrate moieties of gamma-glutamyl transpeptidases purified from rat liver and rat AH-66 hepatoma are quite different. The sugar chains of the liver enzyme were all acidic, while 29% of those of hepatoma enzyme was neutral. Three prominent structural differences were found in the acidic sugar chains of the two enzymes: 1) The liver enzyme has asparagine-linked sugar chains with complete outer chain, NeuAc alpha----Gal beta 1----4GlcNAc, while hepatoma enzyme has sugar chains incomplete in their outer chain moieties; 2) Gal beta 1----4GlcNAc beta 1----4GlcNAc group is found in the sugar chains of liver enzyme but not in those of hepatoma enzyme; 3) More than 40% of the sugar chains of hepatoma enzyme contain bisecting N-acetylglucosamine which is not found in those of liver enzyme.
通过肼解进行的比较研究表明，从大鼠肝脏和大鼠AH - 66肝癌中纯化得到的γ-谷氨酰转肽酶的碳水化合物部分有很大差异。肝脏酶的糖链均为酸性，而肝癌酶的糖链中有29%是中性的。在这两种酶的酸性糖链中发现了三个显著的结构差异：1）肝脏酶具有带有完整外链NeuAcα----Galβ1----4GlcNAc的天冬酰胺连接糖链，而肝癌酶的糖链在外链部分不完整；2）Galβ1----4GlcNAcβ1----4GlcNAc基团存在于肝脏酶的糖链中，而不存在于肝癌酶的糖链中；3）肝癌酶超过40%的糖链含有二分N - 乙酰葡糖胺，而在肝脏酶的糖链中未发现。
