Low-temperature magnetic circular dichroism evidence for the conversion of four-iron-sulphur clusters in a ferredoxin from Clostridium pasteurianum into three-iron-sulphur clusters
Low-temperature magnetic circular dichroism evidence for the conversion of four-iron-sulphur clusters in a ferredoxin from Clostridium pasteurianum into three-iron-sulphur clusters
复制标题
低温磁圆二色性证明巴氏梭菌铁氧还蛋白中的四铁硫簇转化为三铁硫簇
DOI：
10.1016/0005-2728(81)90047-5
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
D. Hall
中科院分区：
文献类型：
--
作者：
A. Thomson;A. Robinson;Michael K. Johnson;R. Cammack;K. Rao;D. Hall
用铁氰化钾氧化巴氏梭菌的8Fe铁氧还蛋白，然后在Sephadex G-25和DE-23纤维素柱上纯化，得到在g 2.01处具有强烈EPR信号的蛋白质。低温磁性圆二色性（MCD）光谱的这种物种是不同的氧化高电位铁蛋白的Chromatium，但相同的铁氧还蛋白II的脱硫弧菌的光谱。在用连二亚硫酸钠还原铁氰化物处理的铁氧还蛋白时，仅获得g因子为2.05、1.94和1.89的弱EPR信号。低温MCD谱具有强烈的温度依赖性，其形式类似于连二亚硫酸盐还原的D。巨铁氧还蛋白II. MCD磁化曲线主要由基态有效g因子为g = 8.0和g = 0.0的物种所控制，这也与最近由低温MCD谱所测得的D.巨铁氧还蛋白II. MCD的特征与连二亚硫酸盐还原的铁氧还蛋白的特征有很大的不同。pasteurianum，未经铁氰化物处理。这建立了铁氰化物处理的Cl中的铁硫簇的密切相似性。pasteurianum ferredoxin和D.巨铁氧还蛋白II.后者是已知的含有一个单一的3Fe中心，类似于观察到的铁氧还蛋白I从固氮菌vinelandii的X-射线晶体学。因此，Cl.巴氏杆菌铁氧还蛋白在用铁氰化物氧化时转化为3Fe簇。
Oxidation of the 8Fe ferredoxin from Clostridium pasteurianum with potassium ferricyanide, followed by purification on Sephadex G-25 and DE-23 cellulose columns, gives a protein with an intense EPR signal at g 2.01. The low-temperature magnetic circular dichroism (MCD) spectra of this species are different from those of the oxidized high-potential iron protein from Chromatium but identical with the spectra of ferredoxin II from Desulphovibrio gigas. On reduction of the ferricyanide-treated ferredoxin with sodium dithionite only a weak EPR signal with g factors of 2.05, 1.94 and 1.89 is obtained. The low-temperature MCD spectra are strongly temperature dependent with a form similar to those of dithionite-reduced D. gigas ferredoxin II. The MCD magnetization curves are dominated by a species with ground-state effective g factors of g ı 8.0 and g⊥ 0.0, which are also similar to those determined recently by low-temperature MCD spectroscopy for D. gigas ferredoxin II. The MCD characteristics are quite different from those of dithionite-reduced ferredoxin from Cl. pasteurianum, untreated with ferricyanide. This establishes the close similarity of the iron-sulphur clusters in ferricyanide-treated Cl. pasteurianum ferredoxin and in D. gigas ferredoxin II. The latter is known to contain a single 3Fe centre, similar to that observed in ferredoxin I from Azotobacter vinelandii by X-ray crystallography. Therefore, it is concluded that the [4Fe-4S] clusters of Cl. pasteurianum ferredoxin are converted to 3Fe clusters on oxidation with ferricyanide.
来自 Azotobacter vinelandii 的 7Fe 铁氧还蛋白的结构。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ghosh,D;FureyJr,W;O'Donnell,S;Stout,CD
通讯作者：
Stout,CD