Magnetic circular dichroism spectroscopy as a probe of axial heme ligand replacement in semisynthetic mutants of cytochrome c.
Magnetic circular dichroism spectroscopy as a probe of axial heme ligand replacement in semisynthetic mutants of cytochrome c.
复制标题
磁性圆二色光谱作为细胞色素 c 半合成突变体中轴向血红素配体替代的探针。
DOI：
10.1016/0014-5793(91)81222-t
复制
发表时间：
1991
期刊：
影响因子：
3.5
通讯作者：
Dawson,JH
中科院分区：
文献类型：
--
作者：
Rux,JJ;Dawson,JH
以组氨酸或半胱氨酸取代80位内源性轴向蛋氨酸配体的马心脏细胞色素在紫外可见区用磁圆二色性（MCD）光谱进行了表征。将突变蛋白在铁状态下的MCD光谱与真实的双咪唑和咪唑/硫酸连接的铁血红素蛋白的MCD光谱进行比较，清楚地表明突变蛋白中80位替代氨基酸的组氨酸-咪唑和半胱氨酸-硫酸基团与血红素铁协调。这项研究证明了MCD光谱在突变血红素蛋白中识别轴向配体的能力。准确的轴向配体分配对于正确解释这种新蛋白质的改变性质至关重要。
Horse heart cytochromecwith either histidine or cysteine replacing the endogenous axial methionine ligand at position 80 has been characterized with magnetic circular dichroism (MCD) spectroscopy in the UV-visible region. Comparison of the MCD spectra of the mutant proteins in the ferric state to those of authentic bis-imidazole- and imidazole/thiolate-ligated ferric heme proteins clearly shows that the histidine-imidazole and cysteine-thiolate groups of the replacement amino acids at position 80 are coordinated to the heme iron in the mutant proteins. This study demonstrates the power of MCD spectroscopy in identifying axial ligands in mutant heme proteins. Accurate axial ligand assignment is essential for proper interpretation of the altered properties of such novel proteins.