Cytochromes c': biological models for the S = 3/2, 5/2 spin-state admixture?
Cytochromes c': biological models for the S = 3/2, 5/2 spin-state admixture?
复制标题
细胞色素 c：S = 3/2、5/2 自旋态混合物的生物模型？
DOI：
10.1021/cr040416l
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发表时间：
2006
期刊：
影响因子：
62.1
通讯作者：
Terner,James
中科院分区：
文献类型：
--
作者：
Weiss,Raymond;Gold,Avram;Terner,James
大多数已知铁血红素蛋白的电子基态要么是低自旋（S) 1/2)，要么是高自旋(S) 5/2）。然而，这些蛋白质中有一小部分不符合这一规律。这一组包括细菌铁细胞色素c '（早期称为RHP，细胞色素c，细胞色素cc '）， 1-4，其磁性一直是争论的主题。在早期的研究中，从红红螺旋菌（Rs. rubrum）、Vinosum染色菌（Ch. Vinosum）和palustris红假单胞菌（Rp. rodopseudomonas palustris）中分离的铁胞色素c′在生理pH和室温下的溶液磁化率测量得出了5.1和4.9µB的磁磁量。palustris)细菌。在1.4 ~ 4.2 K范围内，通过磁化率测量，测定了Ch. Vinosum的铁细胞色素c′的磁矩为3.4µB。这种不寻常的磁性使Ehrenberg和Kamen5提出，电子结构可以用低自旋（S) 1/2)/高自旋(S) 5/2）热平衡来描述。Maltempo等人6-8随后提出了一种基态，其中未受扰动的中自旋（S) 3/2)和高自旋(S) 5/2）态是量子力学混合的。进一步的研究表明，从不同细菌中分离出的铁细胞色素c′具有不同的磁性。主要基于EPR光谱，这些蛋白质似乎由两组组成。第一个
The electronic ground state of most known ferric heme proteins is either low-spin (S) 1/2) or high-spin (S) 5/2). However, a small number of these proteins do not conform to this regime. This group includes the bacterial ferricytochromes c′(earlier known as RHP, cytochromoids c, cytochromes cc′), 1-4 whose magnetic properties have been the subject of debate. In the earliest investigations, magnetic moments of 5.1 and 4.9 µB were deduced from solution magnetic susceptibility measurements made at physiological pH and room temperature for the ferricytochromes c′ isolated from the Rhodospirillum rubrum (Rs. rubrum), Chromatium Vinosum (Ch. Vinosum), and Rhodopseudomonas palustris (Rp. palustris) bacteria. 5 Between 1.4 and 4.2 K, the magnetic moment of the ferricytochrome c′ from Ch. Vinosum was determined to be 3.4 µB by magnetic susceptibility measurements. 6 The unusual magnetic properties led Ehrenberg and Kamen5 to propose that the electronic structure could be described by a low-spin (S) 1/2)/high-spin (S) 5/2) thermal equilibrium. Maltempo et al. 6-8 subsequently proposed a ground state in which the unperturbed mid-spin (S) 3/2) and high-spin (S) 5/2) states are quantum mechanically admixed. Further studies have indicated that magnetic properties vary among the ferricytochromes c′ isolated from different bacteria. Based largely on EPR spectroscopy, these proteins appear to be comprised of two groups. The first