Komoda T, Koyama I
First Department of Biochemistry, Saitama Medical School.
Nihon Rinsho. 1995 May;53(5):1098-105.
Multiple forms of a certain enzyme may result from at least two mechanisms: first, allozymes are coded by distinct genes which exist in separate locus on the chromosome or processed by shuffling of distinct exons on the same genome, and second is this subject, so-called isozymes biosynthesized from single gene subsequently become distinguishable from each other as a result of post-translational modification by protease cleavage (CK), deamidation (AMY) and sugar (ALP, GGT, AMY) or GPI-anchor (ALP) moieties attaching to the enzyme molecules. Therefore, it is interesting to speculate whether alternative forms of the above-mentioned enzymes are true isozymes synthesized from a mRNA from single and/or different cells. In this section, the current topics of these isozymes are commented or discussed.
其一,同工酶由位于染色体上不同位点的不同基因编码,或者由同一基因组中不同外显子的重排产生;其二,即本文所讨论的内容,由单个基因生物合成的所谓同工酶,随后由于蛋白酶切割(肌酸激酶)、脱酰胺作用(淀粉酶)以及糖基(碱性磷酸酶、γ-谷氨酰转移酶、淀粉酶)或糖基磷脂酰肌醇锚定(碱性磷酸酶)部分与酶分子结合所导致的翻译后修饰而彼此区分开来。因此,推测上述酶的不同形式是否为由单个和/或不同细胞的mRNA合成的真正同工酶是很有意思的。在本节中,将对这些同工酶的当前研究热点进行评论或讨论。