Determination of the optical properties of CuA(II) in bovine cytochrome c oxidase using magnetic circular dichroism as an optical detector of paramagnetic resonance.
Determination of the optical properties of CuA(II) in bovine cytochrome c oxidase using magnetic circular dichroism as an optical detector of paramagnetic resonance.
复制标题
使用磁圆二色性作为顺磁共振光学检测器测定牛细胞色素 c 氧化酶中 CuA(II) 的光学性质。
DOI：
10.1016/0162-0134(86)80083-6
复制
发表时间：
1986
影响因子：
3.9
通讯作者：
C. P. Barrett
中科院分区：
文献类型：
--
作者：
Andrew J. Thomson;Colin Greenwood;Jim Peterson;C. P. Barrett
本文用一种新颖的磁性圆二色-微波双共振(MCDODMR)实验研究了牛细胞色素氧化酶中EPR可检测到的铜中心CuA2+的光学性质。通过用适当频率的单色微波束照射样品，可以部分猝灭由于CuA2+引起的特征的MCD强度。通过这种方式，即使在该酶的血红素中心存在重叠的光学跃迁的情况下，也可以识别来自该中心的MCD条带。得到的光谱与本实验室几年前报道的和通过测量MCD磁化特性获得的光谱很好地比较。此外，还分析了在MCD强度与磁场强度的关系图中得到的MCD-ODMR谱线的形状，得到了对MCD光谱有贡献的CuA2+的光学跃迁的相对偏振。在450-850 nm之间观察到的所有谱带主要是在垂直于CuA2+ATG=2.18的g张量分量方向的平面上极化的。这表明，在可见光区引起光学电荷转移跃迁的所有CuA2+配体大致位于基面内。现在可以提出CuA2+的可能结构。
This paper describes the use of a novel magnetic circular dichroism-microwave double resonance (MCDODMR) experiment to study the optical properties of the EPR detectable copper center, CuA2+, in bovine cytochromecoxidase. By irradiating the sample with a monochromatic microwave beam of appropriate frequency it is possible to quench partially the MCD intensity of the features due to CuA2+. In this way the MCD bands from this center have been identified even in the presence of overlapping optical transitions from the haem centers of this enzyme. The resulting spectrum compares well with that reported some years ago from this laboratory and obtained by measuring MCD magnetisation characteristics. In addition the shapes of the MCD-ODMR lines obtained in a plot of MCD intensity against magnetic field strength have been analyzed to yield the relative polarizations of the optical transitions of CuA2+which contribute to the MCD spectrum. All of the bands observed between 450 and 850 nm are predominantly polarized in thexyplane perpendicular to the direction of theg-tensor component of CuA2+atg= 2.18. This suggests that all of the CuA2+ligands that contribute to the optical charge-transfer transitions in the visible region lie approximately in the basal plane. Possible structures for CuA2+can now be suggested.
组氨酸是细胞色素 c 氧化酶中细胞色素 α 3 的轴向配体。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Stevens,TH;Chan,SI
通讯作者：
Chan,SI