Proton exchange rates in transfer RNA as a function of spermidine and magnesium.
Proton exchange rates in transfer RNA as a function of spermidine and magnesium.
复制标题
转移 RNA 中的质子交换率与亚精胺和镁的函数关系。
DOI：
10.1093/nar/11.7.2121
复制
发表时间：
1983
影响因子：
14.9
通讯作者：
Redfield,AG
中科院分区：
文献类型：
--
作者：
Tropp,JS;Redfield,AG
在20至40°C的温度下，在0.12M Na+和各种水平的添加的亚精胺的存在下，通过NMR饱和回收率测量大肠杆菌RNAval、大肠杆菌Met和酵母tRNAPhe的选定质子的溶剂交换速率。还研究了加入Mg++的tRNAVal。零亚精胺和Mg++的交换率表明U8 A14相互作用的早期熔融，与热力学熔融研究雅阁。二次质子的交换率表明早期熔融的T干在tRNAfMet和受体干在tRNAPhe，从热动力学工作与熔融过渡分配矛盾。每个tRNA添加10个亚精胺比添加Na+更有效地稳定二级和三级相互作用，但不如Mg++。添加的亚精胺具有增加Y55 N1质子的交换速率的奇怪效果，同时保护Y55 N3质子免于在所有三种tRNA中交换。添加的Mg++对tRNAVal具有相同的作用。
Solvent exchange rates of selected protons were measured by NMR saturation recovery forE.colitRNAval,E.colifMetand yeast tRNAPhe, at temperatures from 20 to 40°C, in the presence of 0.12M Na+and various levels of added spermidine. tRNAValwas also studied with added Mg++. The exchange rates in zero spermidine and Mg++indicate early melting of the U8 A14 interaction, in accord with thermodynamic melting studies. Exchange rates for secondary protons suggest early melting of the T stem in tRNAfMetand the acceptor stem in tRNAPhe, in contradiction with melting transition assignments from thermo-dynamic work. Addition of 10 spermidines per tRNA stabilizes the secondary and tertiary interactions more effectively than added Na+, but less so than Mg++. Added spermidine has the curious effect of increasing the exchange rate of the Y55 Nl proton, while protecting the Y55 N3 proton from exchange in all three tRNA's. Added Mg++has the same effect on tRNAVal.