THE SITE OF EF 2 INTERACTION OF THE EUKARYOTIC RIBOSOME

延伸因子2与真核细胞核糖体的相互作用 已经研究了很多年，但人们对它知之甚少 它与哪些核糖体成分相互作用，也不知道它是如何催化 伸长周期的移位步骤。建议对此进行调查 EF2‘的核糖体相互作用 与核糖体的因子，并鉴定核糖体的组成成分 与EF 2交互。这些研究将使用预先衍生的EF 2 异型双功能交联剂附着在多个不同的 因子上的站点将被激活以交叉链接到 分离预先形成的EF_2-核糖体复合体后光解核糖体 在鸟嘌呤核苷酸存在下形成的。这种方法论应该 减少非特定交联量，并允许 核糖体成分相对位置的测定 在应该区分其前和前的条件下与EF2交叉连接 结合的易位后部位。同样的方法将被用于 研究ADP-核糖化EF2的相互作用，由催化形成 白喉毒素与核糖体的作用及其相互作用 被催化失活的核糖体失活蛋白破坏 真核细胞核糖体通过未知的机制。 因为蛋白质合成的过程对所有生长的细胞来说都是必不可少的 最重要的是要详细了解这一过程，以便 继续阐明生命过程。同时也是对 白喉毒素与核糖体失活蛋白的作用机制 抑制蛋白质合成是至关重要的，因为这些试剂 被用来构建针对癌细胞的免疫毒素 可能的化疗和这类药物正在被测试为免疫抑制 帮助器官移植的药物。我们知道的越多关于 他们的行动应该有助于他们的治疗应用，并提供 关于真核核糖体功能的更多信息。

The interaction of elongation factor 2(EF 2) with the eukaryotic ribosome has been studied for a number of years but very little is known about the ribosomal components with which it interacts nor how it catalyzes the translocation step of the elongation cycle. It is proposed to investigate the ribosomal interaction of EF 2' by preparing cross-linked complexes of the factor with the ribosome and identify the ribosomal components which interact with EF 2. These studies will use EF 2 prederivatized with a heterobifunctional cross-linking reagent attached at a number of different sites on the factor which will be activated for cross-linking to the ribosome by photolysis after isolation of preformed EF 2-ribosome complexes formed in the presence of guanine nucleotides. This methodology should reduce the amount of nonspecific cross-linking and allow for the determination of the relative position of the ribosomal components cross-linked to EF 2 under conditions which should discrimate its pre- and post-translocation site of binding. The same methodology will be used to examine the interaction of ADP-ribosylated EF 2, formed by the catalytic action of diphtheria toxin, with ribosomes and the interaction of ribosomes damaged by ribosomal inactivating proteins which catalytically inactivate eukaryotic ribosomes by an unknown mechanism. Since the process of protein synthesis is essential for all growing cells it is of primary importance that the process be understood in detail for continued elucidation of the life processes. Also the determination of the mechanism by which diphtheria toxin and the ribosomal inactivating proteins inhibit protein synthesis is of prime importance since these agents are being used to construct immunotoxins directed against cancer cells for possible chemotherapy and such agents are being tested as immunosuppressive agents to aid organ transplantation. The more that is known concerning their action should aid in their therapeutic applications and provide additional information about the function of the eukaryotic ribosome.