Affiliation:
1. Department of Biochemistry, University of London King's College, Strand, London WC2R 2LS, U.K.
Abstract
1. The inhibitory effects of T-2 toxin and trichodermin on poly(U)-directed polyphenylalanine synthesis were studied by using cell-free systems from reticulocytes. Conditions for amino acid incorporation were carefully chosen in an attempt to ensure that the large majority of poly(U) chains bound only one ribosome engaged in protein synthesis and that all such ribosomes carried nascent polyphenylalanine chains containing approximately the same number of residues. 2. Cell-free systems were allowd to synthesize polyphenylalanine, and T-2 toxin and trichodermin were added to the incorporation mixtures at various times. Irrespective of the time of addition, trichodermin (50 μg/ml) inhibited polyphenylalanine synthesis by approx. 70%. In contrast, although T-2 toxin (40 μg/ml), when added at early incubation times, could inhibit polyphenylalanine synthesis with a maximum of 50%, the drug had no effect on the system when added after a critical time-period. 3. It is concluded that although both T-2 toxin and trichodermin can inhibit peptide-bond formation on ribosomes at the level of the peptidyl transferase catalytic centre the presence, on ribosomes, of nascent polyphenylalanine chains above a certain critical chain length excludes T-2 toxin from functional interaction with its receptor site.
Cited by
40 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献