Fando J L, Alaba I, Escarmis C, Fernandez-Luna J L, Mendez E, Salinas M
Eur J Biochem. 1985 May 15;149(1):29-34. doi: 10.1111/j.1432-1033.1985.tb08888.x.
The relationship between the process of rat brain protein synthesis inhibition by restrictocin and mitogillin and the induction of a specific cleavage in 28S rRNA has been examined. Restrictocin or mitogillin at a concentration of 6 nM inhibits protein synthesis to a level of 80%. The inhibition induced by 6 nM alpha-sarcin is of the same order, indicating that those molecules all catalytically inhibit protein synthesis. When restrictocin or mitogillin was reduced and alkylated, a 100-fold higher concentration of these chemically modified molecules was needed in order to obtain the same inhibition as with native molecules, suggesting a close correlation between activity and configuration of the inhibitors. The inhibitory activity of restrictocin or mitogillin was completely lost after oxidation with performic acid. The inhibition of protein synthesis was always correlated with the production of a fragment from the 3'-end of the 28S rRNA. This rRNA fragment had the same electrophoretic mobility as that produced by alpha-sarcin. The 5'-end sequence of the rRNA fragment produced by restrictocin, mitogillin or alpha-sarcin is AGGAA, demonstrating that restrictocin and mitogillin inhibit protein synthesis in the same way as does alpha-sarcin. The conservation of this region of the rRNA from archaebacteria to eukaryotic ribosomes indicates its importance in the elongation process.
已对限制酶和嗜杀素抑制大鼠脑蛋白质合成的过程与28S rRNA中特定切割的诱导之间的关系进行了研究。浓度为6 nM的限制酶或嗜杀素可将蛋白质合成抑制至80%的水平。6 nM的α-肌动蛋白诱导的抑制作用处于同一水平，表明这些分子均催化抑制蛋白质合成。当限制酶或嗜杀素被还原和烷基化后，需要100倍更高浓度的这些化学修饰分子才能获得与天然分子相同的抑制效果，这表明抑制剂的活性与构象之间密切相关。用过甲酸氧化后，限制酶或嗜杀素的抑制活性完全丧失。蛋白质合成的抑制始终与28S rRNA 3'端产生的一个片段相关。该rRNA片段的电泳迁移率与α-肌动蛋白产生的片段相同。由限制酶、嗜杀素或α-肌动蛋白产生的rRNA片段的5'端序列为AGGAA，表明限制酶和嗜杀素抑制蛋白质合成的方式与α-肌动蛋白相同。从古细菌到真核核糖体，rRNA这一区域的保守性表明其在延伸过程中的重要性。
