Gall A, Ellervee A, Bellissent-Funel M C, Robert B, Freiberg A
Laboratoire Léon Brillouin, 91191 Gif-sur-Yvette, France.
Biophys J. 2001 Mar;80(3):1487-97. doi: 10.1016/S0006-3495(01)76121-8.
High-pressure studies on the photochemical reaction center from the photosynthetic bacterium Rhodobacter sphaeroides, strain R26.1, shows that, up to 0.6 GPa, this carotenoid-less membrane protein does not loose its three-dimensional structure at room temperature. However, as evidenced by Fourier-transform preresonance Raman and electronic absorption spectra, between the atmospheric pressure and 0.2 GPa, the structure of the bacterial reaction center experiences a number of local reorganizations in the binding site of the primary electron donor. Above that value, the apparent compressibility of this membrane protein is inhomogeneous, being most noticeable in proximity to the bacteriopheophytin molecules. In this elevated pressure range, no more structural reorganization of the primary electron donor binding site can be observed. However, its electronic structure becomes dramatically perturbed, and the oscillator strength of its Q(y) electronic transition drops by nearly one order of magnitude. This effect is likely due to very small, pressure-induced changes in its dimeric structure.
对球形红细菌R26.1菌株光合反应中心的高压研究表明，在高达0.6吉帕的压力下，这种不含类胡萝卜素的膜蛋白在室温下不会失去其三维结构。然而，傅里叶变换预共振拉曼光谱和电子吸收光谱证明，在大气压至0.2吉帕之间，细菌反应中心的结构在初级电子供体的结合位点经历了多次局部重组。高于该值时，这种膜蛋白的表观压缩性是不均匀的，在接近细菌叶绿素分子处最为明显。在这个高压范围内，不再能观察到初级电子供体结合位点的结构重组。然而，其电子结构受到极大干扰，其Q(y)电子跃迁的振子强度下降了近一个数量级。这种效应可能是由于其二聚体结构中由压力引起的非常小的变化。
