Fernandez-Puentes C, Benson S, Olsnes S, Pihl A
Eur J Biochem. 1976 May 1;64(2):437-43. doi: 10.1111/j.1432-1033.1976.tb10320.x.
The inactivation of rabbit reticulocyte ribosomes by abrin and ricin A-chains was studied by incubating ribosomes with the A-chains and testing, after various periods of time, aliquots of the ribosomes for their ability to polymerize phenylalanine. The presence of elongation factor 2 (EF-2) reduced the rate of inactivation of ribosomes by the A-chains. The protective effect of EF-2 was strongly enhanced by GTP and, to a lesser extent, also by GDP or dGTP. Other nucleotides had no demonstrable effect. Much less protection was found after binding of Phe-tRNA to ribosomes in the presence of EF-1 (enzymic binding) or in the presence of high Mg2+ concentration (non-enzymic binding). The data indicate that when EF-2 binds to the ribosomes it completely or partially covers the target site for abrin and ricin A-chains. The possibility that EF-1 also binds to this site is discussed.
通过将核糖体与相思豆毒素和蓖麻毒素A链一起孵育，并在不同时间段后检测核糖体等分试样聚合苯丙氨酸的能力，研究了相思豆毒素和蓖麻毒素A链对兔网织红细胞核糖体的失活作用。延伸因子2（EF-2）的存在降低了A链对核糖体的失活速率。GTP强烈增强了EF-2的保护作用，GDP或dGTP在较小程度上也有增强作用。其他核苷酸没有明显作用。在存在EF-1（酶促结合）或高Mg2+浓度（非酶促结合）的情况下，苯丙氨酰-tRNA与核糖体结合后，发现保护作用要小得多。数据表明，当EF-2与核糖体结合时，它会完全或部分覆盖相思豆毒素和蓖麻毒素A链的靶位点。文中还讨论了EF-1也结合到该位点的可能性。
Zotero 插件