Cherbas L, London I M
Proc Natl Acad Sci U S A. 1976 Oct;73(10):3506-10. doi: 10.1073/pnas.73.10.3506.
In the absence of added hemin, protein synthesis in a rabbit reticulocyte lysate declines abruptly (shuts off) after about 5 min at 30 degrees. In these studies we have examined the basis for the lag period preceding shut-off. The initiation factor that binds Met-tRNAf, previously shown to be rate-limiting in inhibited, heme-deficient lysates, is found to be used stoichiometrically in the presence of excess inhibitor. We suggest that a principal effect of the inhibitor is to impair the recycling of the Met-tRNAf-binding factor; the lag period is attributable largely to the presence of a pool of excess Met-tRNAf-binding factor, which, once used in initiation, cannot be recycled because of the action of the inhibitor.
在没有添加血红素的情况下,兔网织红细胞裂解物中的蛋白质合成在30℃下约5分钟后会突然下降(停止)。在这些研究中,我们研究了停止前延迟期的基础。先前已证明在受抑制的、血红素缺乏的裂解物中结合Met-tRNAf的起始因子是限速因子,发现在存在过量抑制剂的情况下,它按化学计量被使用。我们认为抑制剂的主要作用是损害Met-tRNAf结合因子的再循环;延迟期很大程度上归因于过量Met-tRNAf结合因子池的存在,一旦在起始过程中被使用,由于抑制剂的作用就无法再循环。