Damaso Christopher O, Bunce Richard A, Barybin Mikhail V, Wilks Angela, Rivera Mario
Department of Chemistry, The University of Kansas, Lawrence, Kansas 66045-7582, USA.
J Am Chem Soc. 2005 Dec 21;127(50):17582-3. doi: 10.1021/ja055099u.
A biosynthetic and enzymatic method was developed for the preparation of 13C-labeled verdoheme, which permits the 13C NMR spectroscopic characterization of this elusive intermediate in the heme oxidation path catalyzed by the enzyme heme oxygenase. The 13C NMR data indicate that the ferrous verdoheme complex of Neisseria meningitides heme oxygenase is hexacoordinate and diamagnetic, with a proximal histidine and likely a distal hydroxide as axial ligands. The coordination number and spin state of the ferrous verdoheme-heme oxygenase complex is in stark contrast to the pentacoordinate and paramagnetic nature of the heme-heme oxygenase complex and heme centers in general.
开发了一种生物合成和酶促方法来制备13C标记的胆绿血红素，这使得能够通过13C核磁共振光谱对这种在血红素加氧酶催化的血红素氧化途径中难以捉摸的中间体进行表征。13C核磁共振数据表明，脑膜炎奈瑟菌血红素加氧酶的亚铁胆绿血红素复合物是六配位且抗磁性的，有一个近端组氨酸和可能一个远端羟基作为轴向配体。亚铁胆绿血红素 - 血红素加氧酶复合物的配位数和自旋状态与血红素 - 血红素加氧酶复合物和一般血红素中心的五配位和顺磁性性质形成鲜明对比。
