Malmerberg Erik, M Bovee-Geurts Petra H, Katona Gergely, Deupi Xavier, Arnlund David, Wickstrand Cecilia, Johansson Linda C, Westenhoff Sebastian, Nazarenko Elena, Schertler Gebhard F X, Menzel Andreas, de Grip Willem J, Neutze Richard
Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden.
Department of Biochemistry, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, Netherlands.
Sci Signal. 2015 Mar 10;8(367):ra26. doi: 10.1126/scisignal.2005646.
Rhodopsin is the G protein-coupled receptor (GPCR) that serves as a dim-light receptor for vision in vertebrates. We probed light-induced conformational changes in rhodopsin in its native membrane environment at room temperature using time-resolved wide-angle x-ray scattering. We observed a rapid conformational transition that is consistent with an outward tilt of the cytoplasmic portion of transmembrane helix 6 concomitant with an inward movement of the cytoplasmic portion of transmembrane helix 5. These movements were considerably larger than those reported from the basis of crystal structures of activated rhodopsin, implying that light activation of rhodopsin involves a more extended conformational change than was previously suggested.
视紫红质是一种G蛋白偶联受体（GPCR），在脊椎动物中作为暗光视觉受体。我们利用时间分辨广角X射线散射，在室温下探测视紫红质在其天然膜环境中的光诱导构象变化。我们观察到一种快速的构象转变，这与跨膜螺旋6的胞质部分向外倾斜以及跨膜螺旋5的胞质部分向内移动相一致。这些运动比基于活化视紫红质晶体结构所报道的运动要大得多，这意味着视紫红质的光激活涉及比先前认为的更广泛的构象变化。
