ROS DISC MEMBRANE CHANGES DURING RETINAL DEGENERATION

光诱导杆状体内cGMP磷酸二酯酶(PDE)的激活 光感受器的片段被认为是 光传导过程。这种激活是由GTP结合介导的 蛋白质复合体(G-蛋白质)。 虽然G蛋白和PDE都是从牛和 青蛙视网膜，到目前为止，还不知道是否有实际的结构变化 在区域退行性变过程中发生在这些蛋白质中。我们将决定 无论是数量上还是质量上的生化变化，都发生在 来自RD鼠标的ROS PDE。受影响的RD小鼠的光感受器 缺乏光激活的PDE活性导致高cGMP 水平和视网膜退化。 我们发现PDE蛋白存在于10日龄的RD中 老鼠。然而，它不起作用。 使用最新开发的对小于NG敏感的技术 我们将使用1)识别和定量正常和RD小鼠PDE的水平 Western blotting和放射免疫分析，2)纯化蛋白质 免疫亲和程序，3)表征生化变化， 在视网膜退行性变过程中发生在这些蛋白质中 肽图谱、光亲和标记和抗体结构探测， 4)用重建的方法阐明RD-PDE的功能缺陷 系统。这些数据将提供结构和 视网膜ROS盘膜PDE的数量变化 RD小鼠退行性变。最终，这些数据可能有助于 开发药物以控制或防止细菌的退化 感光细胞。

Light-induced activation of a cGMP phosphodiesterase (PDE) in rod outer segments of photoreceptors has been suggested to be a key step in the phototransduction process. This activation is mediated by a GTP-binding protein complex (G-protein). Although both the G-protein and the PDE have been purified from bovine and frog retina, to date, nothing is known of whether actual structural changes occur in these proteins during reginal degeneration. We will determine both quantitative and qualitative biochemical changes which occur in the ROS PDE from the rd mouse. The photoreceptors from the affected rd mice are deficient in a light-activated PDE activity resulting in high cGMP levels and retinal degeneration. We have found that the PDE protein is present in 10 day-old affected rd mice. However, it is not functional. Using recently developed techniques which are sensitive to less than ng levels we will 1) identify and quantitate normal and rd mouse PDE using western blotting and radioimmunoassays, 2) purify the proteins by immunoaffinity procedures, 3) characterize the biochemical changes which occur in these proteins during retinal degeneration using 2-dimensional peptide mapping, photoaffinity labelling, and antibody structural probing, and 4) elucidate the functional defects in the rd PDE using reconstitution systems. These data will provide basic knowledge of the structural and quantitative changes which occur in ROS disc membrane PDE during retinal degeneration in the rd mouse. Ultimately these data may aid in the development of drugs to control or prevent the degeneration of photoreceptor cells.