The lipid environment plays a crucial role for the function of membrane proteins. We analyzed the influence of various lipid properties on the photoreceptors Bacteriorhodopsin (BR) and Proteorhodopsin (PR) by time-resolved step-scan FTIR spectroscopy. The photoreceptors were reconstituted into liposomes thereby providing an uniform biomimetic membrane, and the physical properties of the lipids were systematically varied. The lipid phase alters significantly the protonation dynamics of both, BR and PR. We also analyzed the conformational changes of the photoreceptors during the proton pumping mechanism and could demonstrate that a lipid-induced altered protonation dynamics is correlated to an altered conformational dynamics. Our results indicate that the fluidity of the membrane environment directly influences the structural-functional correlation.

脂质环境对于膜蛋白的功能起着至关重要的作用。我们通过时间分辨步进扫描FTIR光谱分析了各种脂质性质对光感受器细菌视紫红质（BR）和蛋白视紫红质（PR）的影响。将光感受器重构为脂质体，从而提供均匀的仿生膜，并且脂质的物理性质被系统地改变。脂质相显着改变了BR和PR的质子动力学。我们还分析了质子泵浦机制期间感光器的构象变化，并可以证明脂质诱导的质子化动力学改变与构象动力学改变有关。我们的结果表明，膜环境的流动性直接影响结构-功能的相关性。