Dürr Ulrich H N, Yamamoto Kazutoshi, Im Sang-Choul, Waskell Lucy, Ramamoorthy Ayyalusamy
Biophysics Research Division and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
J Am Chem Soc. 2007 May 30;129(21):6670-1. doi: 10.1021/ja069028m. Epub 2007 May 9.
Cytochrome b5 (cyt b5) is a membrane-anchored electron-carrier protein containing a heme in its soluble domain. It enhances the enzymatic turnover of selected members of the cytochrome P450 superfamily of catabolic enzymes, localized in the endoplasmic reticulum of liver cells. Remarkably, its alpha-helical membrane-anchoring domain is indispensable for the cyt b5/cyt P450 interaction. Here, we present the first solid-state NMR studies on holo-cyt b5 in a membrane environment, namely, macroscopically oriented DMPC:DHPC bicelles. We have presented approaches to selectively investigate different domains of the protein using spectral editing NMR techniques that utilize the unique motional properties of each domain. Two-dimensional 1H-15N HIMSELF spectra showed PISA-wheel patterns reporting on the structure and dynamics of the membrane anchor of the protein.
细胞色素b5（cyt b5）是一种膜锚定电子载体蛋白，其可溶性结构域中含有一个血红素。它能增强细胞色素P450分解代谢酶超家族中特定成员的酶促周转率，这些酶定位于肝细胞的内质网中。值得注意的是，其α-螺旋膜锚定结构域对于cyt b5/cyt P450相互作用不可或缺。在此，我们展示了在膜环境中对全细胞色素b5进行的首次固态核磁共振研究，即宏观取向的二肉豆蔻酰磷脂酰胆碱：二己酰磷脂酰胆碱双分子层。我们提出了利用光谱编辑核磁共振技术选择性研究蛋白质不同结构域的方法，该技术利用了每个结构域独特的运动特性。二维1H-15N HIMSELF谱显示出PISA轮模式，反映了蛋白质膜锚定结构域的结构和动力学。
