MOLECULAR MECHANISMS CONTROLLING BACTERIORHODOPSIN

细菌视紫红质可能是最简单的生物能量传导器。 它使用光能，被一种26kD的小蛋白质吸收，以运输 穿过细胞膜的质子。已经取得了很大的进展 关于追踪质子穿过细胞膜的路径 --“会发生什么”的问题即将得到解决， 我们提出了一些实验来阐明质子释放部分。 在这一过程中。我们现在已经开始在下一步取得一些进展 问题层次--提出一些明确的假设 质子转移过程和生色团的机制 异构化--“事情是如何发生的”之类的问题。我们是 准备利用我们实验室的一项重大发现，即 两个质子化基团的pk可以解释为什么质子从 质子化的席夫碱到它的反离子可以导致释放 离初始质子约20埃单位的一群质子 调职。我们还开发了新的方法来确定 BR中残基突变对质子转移的影响 过程--通过它们对质子pk耦合的影响 转接组。高分辨率结构的出现将 继续进行我们提出的功能实验 细菌视紫红质作为细菌视紫红质越来越重要 继续建立自己的经典系统，研究一些 生物学中的基本问题。

Bacteriorhodopsin is probably the simplest biological energy transducer. It uses light energy, absorbed by a small 26kD protein, to transport protons across the cell membrane. A great deal of progress has been made on tracing out the pathway of the protons across the cell membrane - the "what happens" kinds of questions are close to being solved and we propose a number of experiments to clarify the proton release part of this process. We have now started to make some progress on the next level of questions - proposing some definite hypotheses about the mechanisms of the proton transfer processes and chromophore isomerization - the "how things happen" kinds of questions. We are poised to exploit a major finding from our lab, that the coupling of the pK's of two protonatable groups can explain why proton transfer from the protonated Schiff base to its counter ion can lead to the release of a proton from a group ca. 20 Angstrom units away from the initial proton transfer. We also have developed new methods for determining the effects of mutations of the residues in bR on the proton transfer process -by their effect on the coupling of the pK's of the proton transfer groups. The appearance of high resolution structures will continue to make the functional experiments we propose on bacteriorhodopsin more and more important, as bacteriorhodopsin continues to establish itself as a classic system to study some fundamental questions in biology.