Park Sang Ho, Mrse Anthony A, Nevzorov Alexander A, De Angelis Anna A, Opella Stanley J
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0307, USA.
J Magn Reson. 2006 Jan;178(1):162-5. doi: 10.1016/j.jmr.2005.08.008. Epub 2005 Oct 6.
Solid-state NMR experiments on mechanically aligned bilayer and magnetically aligned bicelle samples demonstrate that membrane proteins undergo rapid rotational diffusion about the normal in phospholipid bilayers. Narrow single-line resonances are observed from 15N labeled sites in the trans-membrane helix of the channel-forming domain of the protein Vpu from HIV-1 in phospholipid bilayers with their normals at angles of 0 degrees, 20 degrees, 40 degrees, and 90 degrees, and bicelles with their normals at angles of 0 degrees and 90 degrees with respect to the direction of the applied magnetic field. This could only occur if the entire polypeptide undergoes rotational diffusion about the bilayer normal. Comparisons between experimental and simulated spectra are consistent with a rotational diffusion coefficient (DR) of approximately 10(5)s-1.
对机械排列的双层膜和磁排列的双分子层样品进行的固态核磁共振实验表明，膜蛋白在磷脂双层膜中围绕法线进行快速旋转扩散。在HIV-1的蛋白Vpu通道形成结构域的跨膜螺旋中，从15N标记位点观察到窄的单线共振，这些磷脂双层膜的法线与施加磁场方向的夹角为0度、20度、40度和90度，以及法线与施加磁场方向的夹角为0度和90度的双分子层。只有当整个多肽围绕双层膜法线进行旋转扩散时，才会出现这种情况。实验光谱与模拟光谱之间的比较与约10(5)s-1的旋转扩散系数(DR)一致。
