Ades I Z, Harpe K G
Biochem J. 1982 Aug 1;205(2):257-63. doi: 10.1042/bj2050257.
We presented evidence indicating that the established procedure for purifying delta-aminolaevulinate (ALA) synthase from embryonic-chick liver yielded an enzyme with a partially degraded subunit of molecular weight 51000 [Ades & Harpe (1981) J. Biol. Chem. 256, 9329-9333]. We now report the purification from livers of porphyric embryos of a preparation of ALA synthase which consisted primarily of a 63000-Da polypeptide and a component migrating as a smear of polypeptides with a minimum molecular weight of 52 000. Neither component could be recovered from liver mitochondria of normal embryos, where the amounts of ALA synthase were relatively low. The 52 000-Da component had been established to be the partially degraded subunit of the enzyme. Peptide-mapping analyses indicated that the 63 000- and the 52 000-Da components possessed significant structural homologies, and it was concluded that the 63 000-Da polypeptide represented the mature subunit of ALA synthase.
我们提供的证据表明，从胚胎鸡肝脏中纯化δ-氨基乙酰丙酸（ALA）合酶的既定程序产生了一种酶，其亚基部分降解，分子量为51000 [阿德斯和哈珀（1981年）《生物化学杂志》256, 9329 - 9333]。我们现在报告从卟啉胚胎肝脏中纯化的一种ALA合酶制剂，它主要由一条63000道尔顿的多肽和一个迁移为分子量至少为52000的多肽条带的成分组成。在正常胚胎的肝脏线粒体中，这两种成分均无法找到，因为那里ALA合酶的含量相对较低。已确定52000道尔顿的成分是该酶部分降解的亚基。肽图谱分析表明，63000道尔顿和52000道尔顿的成分具有显著的结构同源性，由此得出结论，63000道尔顿的多肽代表ALA合酶的成熟亚基。
