A rapid spectrophotometric assay for ferrochelatase activity in preparations containing much endogenous hemoglobin and its application to soybean root-nodule preparations.
A rapid spectrophotometric assay for ferrochelatase activity in preparations containing much endogenous hemoglobin and its application to soybean root-nodule preparations.
复制标题
内源性血红蛋白较多制剂中亚铁螯合酶活性的快速分光光度测定及其在大豆根瘤制剂中的应用。
DOI：
10.1016/0003-2697(75)90707-1
复制
发表时间：
1975
影响因子：
2.9
通讯作者：
R. J. Porra
中科院分区：
文献类型：
--
作者：
R. J. Porra
本文介绍了一种简便、快速的铁络合酶(EC4.99.1.1)活性的分光光度测定法，适用于含有大量血红蛋白的酶制剂。在该方法中，以中卟啉IX为底物，通过记录还原减去氧化的吡啶血红素光谱来测定产物中的中位血红素IX。吡啶中血红素在547 nm处有一个α峰，在531 nm处有一个谷，而来自血红蛋白的吡啶原血红素的α峰和谷分别在557和541 mm。因此，原血色素对E1cm547-531 nm的贡献很小，这是允许的，因此该方法给出了非常可靠的中铁血红素IX形成的数量的测定。结果表明，大豆根瘤铁络合酶活性90%以上存在于类菌体细胞中，而在植物线粒体中不到10%，在可溶性植物部分中未检测到。
A simple and rapid spectrophotometric assay for ferrochelatase (EC 4.99.1.1) activity is described which is suitable for use with enzyme preparations containing large amounts of hemoglobin. In this method mesoporphyrin IX is used as substrate and the product, mesoheme IX, is measured by recording the reduced minus the oxidized pyridine hemochrome spectrum. Pyridine mesohemochrome has an α peak at 547 nm and a trough at 531 nm while the α peak and trough of pyridine protohemochrome (from hemoglobin) are at 557 and 541 mm, respectively. Thus the contribution of the protohemochrome to E1cm547-531nm, which can be allowed for, is small, and so the method gives very reliable determinations of the amounts of mesoheme IX formed. By means of this assay, it was shown that in excess of 90% of the ferrochelatase activity of soybean root-nodules is present in the bacteroid cells and less than 10% in the plant mitochondria: No ferrochelatase activity could be detected in the soluble plant fraction.