Phosphorus-31 nuclear magnetic resonance of double- and triple-helical nucleic acids. Phosphorus-31 chemical shifts as a probe of phosphorus-oxygen ester bond torsional angles.
Phosphorus-31 nuclear magnetic resonance of double- and triple-helical nucleic acids. Phosphorus-31 chemical shifts as a probe of phosphorus-oxygen ester bond torsional angles.
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双螺旋和三螺旋核酸的磷 31 核磁共振。
DOI：
10.1021/bi00532a026
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Vegeais,D
中科院分区：
文献类型：
--
作者：
Gorenstein,DG;Luxon,BA;Goldfield,EM;Lai,K;Vegeais,D
大卫G. Gorenstein，John * 布鲁斯A.作者：Lucon，Evelyn M.戈德菲尔德，Kofen Lai和Donna Vegei摘要：给出了poly [d（GC）]* poly [d（GC）]，d（GC）4，苯丙氨酸tRNA（酵母）和poly（A）+ oligo（U）混合物的31 P NMR谱的温度依赖性。互补RNA和聚d（GC）自身互补DNA的混合物的31 P NMR光谱提供了双螺旋、三螺旋和“Z”螺旋中磷酸酯构象的扭转信息。单链核酸随温度的增加的低场位移提供了磷酸酯变化的测量，最近提出磷酸酯中的31 P化学位移可以作为P-0酯键扭转角的直接探针。这两种理论考虑[Gorenstein & Kar，1975;也可参见Gorenstein（1975，1978，1981）和Pradd et al.（1979）]和该假设的直接实验检验[Gorenstein等人，一九七六年; Gorenstein & Luxon，1979;饰Patel（1979 a，B）和Gueron和Shulman（1975）]证实了磷酸二酯单阴离子的31 P信号在一个gauche，gg 1构象（如在螺旋状态中发现的）应该与非农戈切构象中的二酯在高场共振百万分之几这些结论被证明是特别有意义的，因为其他光谱探针不能提供核酸中磷酸酯键的详细构象信息。由于现在认为在很大程度上定义核酸构象结构的六个扭转角中，两个PO酯扭转角为核酸主链提供了主要的构象柔性（Kim
David G. Gorenstein,*'* Bruce A. Luxon, Evelyn M. Goldfield, Kofen Lai, and Donna Vegeais abstract: Thetemperature dependence to the 31P NMR spectra of poly [d (GC)]* poly [d (GC)], d (GC) 4, phenylalanine tRNA (yeast) and mixtures of poly (A)+ oligo (U) is presented. The 31P NMR spectra of mixtures of complementary RNA and of the poly d (GC) self-complementary DNA provide torsional information on the phosphate ester conformation in the double, triple, and “Z” helix. The increasing downfield shift with temperature for the single-strand nucleic acids provides a measure of the change in the phosphate ester have recently proposed that 31P chemical shifts in phosphate esters may serve as a direct probe of P-0 ester bond torsional angles. Both theoretical considerations [Gorenstein & Kar, 1975; see also Gorenstein (1975, 1978, 1981) and Pradd et al.(1979)] and direct experimental tests of this hypothesis [Gorenstein et al., 1976; Gorenstein & Luxon, 1979; see also Patel (1979a, b) and Gueron & Shulman (1975)] confirm that the 31P signal of a phosphate diester monoanion in a gauche, gauche (gg) 1 conformation (as found in the helix state) should resonate several parts per million upfield from a diester in a nongauche conformation (as found in the random coil state).These conclusions prove to be especiallysignificant since other spectroscopic probes fail to provide detailed conformational information on the phosphate ester bonds in the nucleic acids. Since it is now believed that of the six torsional angles that largely definethe conformational structure of nucleic acids, the two PO ester torsional angles provide themain conformational flexibility to the nucleic acid backbone (Kim