论文部分内容阅读
亚铁螯合酶(ferrochelatase)(EC 4.99.1.1)亦称血红素合成酶(heme synthetase)或血红素亚铁裂合酶(Protoheme ferro-lyase),是血红素生物合成中的最终酶,它催化亚铁离子嵌入原卟啉Ⅸ形成血红素.该酶普遍存在于动植物和微生物中,在动物体,主要是肝内,位于细胞线粒体膜内侧,为膜结合酶.血红素的生物合成是以甘氨酸、琥珀酰辅酶A和两价铁离子为基本原料,经一系列酶的催化生成原卟啉Ⅸ,后者受亚铁螯合酶的催化与Fe~(2+)螯合生成血红素(图1). 有趣的是,在血红素的合成途径中,只是开始和最后步骤是在细胞线粒体内进行的.生成的δ氨基γ-酮戊酸(ALA)入细胞质,在那里合成卟胆原、尿卟啉原Ⅲ和粪卟啉原Ⅲ等中间物,然后又回到线粒体.经原卟啉Ⅸ合成血红素.在血红素合成的调节中,起着重要作用的两种酶是ALA合成酶和亚铁整合酶.ALA合
Ferrochelatase (EC 4.99.1.1), also known as heme synthetase or Protoheme ferro-lyase, is the ultimate enzyme in heme biosynthesis, which Catalytic ferrous ions are embedded in protoporphyrin Ⅸ form heme.The enzyme is ubiquitous in animals and plants and microorganisms, in the animal body, mainly in the liver, located inside the mitochondrial membrane of the cells, is a membrane-bound enzyme heme biosynthesis is With glycine, succinyl coenzyme A and ferrous iron as the basic raw materials, a series of enzymes catalyzed the protoporphyrin Ⅸ, the latter is catalyzed by ferrous chelatase and Fe ~ (2+) chelation heme (Figure 1) Interestingly, in the heme biosynthetic pathway, only the beginning and last steps are performed within the mitochondria of the cells, the resulting δ amino-γ-keto-valeric acid (ALA) enters the cytoplasm where it is synthesized Protoporphyrinogen Ⅲ and coproporphyrinogen Ⅲ and other intermediates, and then returned to the mitochondria .Proporphyrin Ⅸ heme synthesis in the regulation of heme synthesis, two enzymes play an important role in the ALA Synthase and ferrous integrase