Fujinaga J, Gaillard J, Meyer J
Département de Biologie Moléculaire et Structurale, SESAM-SCPM, CENG 85X, Grenoble, France.
Biochem Biophys Res Commun. 1993 Jul 15;194(1):104-11. doi: 10.1006/bbrc.1993.1791.
The [2Fe-2S] ferredoxin from Clostridium pasteurianum contains five cysteine residues in positions 11, 14, 24, 56 and 60. Residues 24, 56 and 60 have been separately mutated into serine. The modified ferredoxins have been purified and were all found to contain a [2Fe-2S]-type cluster. The electronic absorption and EPR spectra of the C24S protein were only slightly different from those of the native one. In contrast, the C56S and C60S ferredoxins displayed spectroscopic features witnessing the presence of an oxygen ligand to the iron-sulfur cluster: the UV-visible absorption bands were shifted to higher energy by ca. 20 nm, and the high field components of the EPR spectra were shifted from gx = 1.92 and gy = 1.95 to gx = 1.88 and gy = 1.92, respectively.
来自巴斯德梭菌的[2Fe-2S]铁氧化还原蛋白在第11、14、24、56和60位含有五个半胱氨酸残基。第24、56和60位的残基已分别突变为丝氨酸。修饰后的铁氧化还原蛋白已被纯化，并且均被发现含有一个[2Fe-2S]型簇。C24S蛋白的电子吸收光谱和电子顺磁共振光谱与天然蛋白的光谱仅略有不同。相比之下，C56S和C60S铁氧化还原蛋白显示出的光谱特征表明铁硫簇存在氧配体：紫外可见吸收带向更高能量移动了约20 nm，电子顺磁共振光谱的高场分量分别从gx = 1.92和gy = 1.95移至gx = 1.88和gy = 1.92。
