George G N, Cramer S P, Frey T G, Prince R C
Exxon Research and Engineering Co., Annandale, NJ.
Biochim Biophys Acta. 1993 May 6;1142(3):240-52. doi: 10.1016/0005-2728(93)90152-6.
The polarized X-ray absorption spectra of the copper, iron and zinc sites of mitochondrial cytochrome oxidase in oriented membrane multilayers have been examined. The copper X-ray absorption edge spectra indicate the presence of a tetragonal copper, which we assign as CuB, oriented with the long axis approximately orthogonal to the membrane normal. We have also detected the presence of a relatively long (2.6 A) Cu-S or Cu-Cl interaction, which we assign to a copper-thioether (probably Met210) coordination at the CuA site, with the bond oriented along the membrane normal. The coordination of the zinc, the iron and the CuB heme a3 binuclear site are discussed.
已对取向膜多层中的线粒体细胞色素氧化酶的铜、铁和锌位点的偏振X射线吸收光谱进行了研究。铜X射线吸收边光谱表明存在四方铜，我们将其指定为CuB，其长轴大致与膜法线正交。我们还检测到存在相对较长（2.6埃）的铜-硫或铜-氯相互作用，我们将其归因于CuA位点处的铜-硫醚（可能是Met210）配位，键沿膜法线方向取向。讨论了锌、铁和CuB血红素a3双核位点的配位情况。
