External Transesterification of Ribonucleotide Esters Naturally Catalyzed by Large Ribozymes
作者:Christo D. Roussev、Gabriela D. Ivanova、Emilia K. Bratovanova、Nikolay G. Vassilev、Dimiter D. Petkov
DOI:10.1021/ja990491r
日期:1999.12.1
The intriguing chemical mechanism of the external transesterification by which large ribozymes (group I, group II, and spliceosomal introns) splice RNA has been found to operate in the methanolysis of ribonucleoside 2'-/3'-dimethyl phosphates in non-hydrogen-bonding organic solvents. Besides needing aprotic organic media this mechanism requires a high concentration of the attacking alcohol accounting
已发现大核酶(I 组、II 组和剪接体内含子)剪接 RNA 的外部酯交换的有趣化学机制在非氢键中核糖核苷 2'-/3'-磷酸二甲酯的甲醇分解中起作用有机溶剂。除了需要非质子有机介质外,该机制还需要高浓度的攻击性酒精,以解释 I 组内含子与外部鸟苷的结合以及 II 组和剪接体内含子使用不相邻的内部 2'-OH。这一发现是核糖核苷酸酯的外部非核酶酯交换的第一个例子,也是加速这一关键生化反应的手段。
STUDY ON THE THERMOLYSIS OF 5′-O-TRITYL-2′,3′-O-TRIPHENYL-PHOSPHORANEDIYLURIDINE
A new method is introduced by thermolysis of 5 ' -O-trityl-2 ' ,3 ' -O-triphenylphosphoranediyluridine (4) with or without the presence of methanol to afford the 3-N-methyl-5 ' -O-trityluridine (9) and 5 ' -O-trityl-2,2 ' -cyclouridine (5), respectively. Mechanism for this thermolysis is also proposed.