Reaction of cyanide with cytochrome ba3 from Thermus thermophilus: spectroscopic characterization of the Fe(II)a3-CN.Cu(II)B-CN complex suggests four 14N atoms are coordinated to CuB.
Reaction of cyanide with cytochrome ba3 from Thermus thermophilus: spectroscopic characterization of the Fe(II)a3-CN.Cu(II)B-CN complex suggests four 14N atoms are coordinated to CuB.
复制标题
氰化物与嗜热栖热菌细胞色素 ba3 的反应：Fe(II)a3-CN.Cu(II)B-CN 复合物的光谱表征表明四个 14N 原子与 CuB 配位。
DOI：
10.1073/pnas.89.8.3195
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发表时间：
1992
影响因子：
11.1
通讯作者：
Fee,JA
中科院分区：
文献类型：
--
作者：
Surerus,KK;Oertling,WA;Fan,C;Gurbiel,RJ;Einarsdóttir,O;Antholine,WE;Dyer,RB;Hoffman,BM;Woodruff,WH;Fee,JA
Cytochrome ba3 from Thermus thermophilus reacts slowly with excess HCN at pH 7.4 to create a form of the enzyme in which CuA, cytochrome b, and CuB remain oxidized, while cytochrome a3 is reduced by one electron, presumably with the formation of cyanogen. We have examined this form of the enzyme by UV-visible, resonance Raman, EPR, and electron nuclear double resonance spectroscopies in conjunction with permutations of 13C- and 15N-labeled cyanide. The results support a model in which one CN- binds through the carbon atom to ferrous a3, supporting a low-spin (S = 0) configuration on the Fe; bridging by this cyanide to the CuB is weak or absent. Four 14N atoms, presumably donated by histidine residues of the protein, provide a strong equatorial ligand field about CuB; a second CN- is coordinated through the carbon atom to CuB in an axial position.
