Isolation and characterization of methylmalonyl-CoA mutase from human placenta.
Isolation and characterization of methylmalonyl-CoA mutase from human placenta.
复制标题
从人胎盘中分离和表征甲基丙二酰辅酶A变位酶。
DOI：
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发表时间：
1980
影响因子：
4.8
通讯作者：
R. Allen
中科院分区：
文献类型：
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作者：
J. Kolhouse;C. Utley;R. Allen
甲基丙二酰辅酶A是存在于哺乳动物组织中的两种已知钴胺素依赖性酶之一，已利用5 ′-脱氧腺苷钴胺素-琼脂糖凝胶上的亲和层析作为主要纯化步骤从2.5 kg人胎盘中分离。该酶在聚丙烯酰胺盘状凝胶电泳上呈单一条带。该酶的Mr为145，000，它有两个Mr = 72，000的亚基。氨基酸分析揭示了与其他人钴胺素结合蛋白的主要差异。基于X射线荧光，该酶具有2摩尔结合的钴胺素/摩尔酶。与纯化的钴胺素转运蛋白相反，大多数与酶结合的钴胺素在KCN存在下在低pH下煮沸或对含有0.2 M二硫苏糖醇的7.5 M胍透析或两者都不释放，这表明钴胺素可能共价连接到纯化的酶上。在鸡体内已经产生了沉淀抗体和抑制酶活性的抗体。
Methylmalonyl-CoA mutase, one of two known cobalamin-dependent enzymes present in mammalian tissues, has been isolated from 2.5 kg of human placenta utilizing affinity chromatography on 5'-deoxyadenosylcobalamin-Sepharose as the major purification step. The enzyme gives a single band on polyacrylamide disc gel electrophoresis. The Mr of the enzyme is 145,000 and it has two subunits of Mr = 72,000. Amino acid analysis reveals major differences from other human cobalamin-binding proteins. Based on x-ray fluorescence, the enzyme has 2 mol of cobalamin bound/mol of enzyme. In contrast to purified cobalamin transport proteins, most of the cobalamin bound to the enzyme is not released by boiling at low pH in the presence of KCN, or dialysis against 7.5 M guanidine containing 0.2 M dithiothreitol, or both, suggesting the possibility that cobalamin may be covalently attached to the purified enzyme. Both precipitating antibodies and antibodies that inhibit enzyme activity have been raised in a chicken.