Comparative structural analysis of 1-methyladenosine, 7-methylguanosine, ethenoadenosine and their protonated salts IV: 1H, 13C, and 15N NMR studies at natural isotope abundance.
Comparative structural analysis of 1-methyladenosine, 7-methylguanosine, ethenoadenosine and their protonated salts IV: 1H, 13C, and 15N NMR studies at natural isotope abundance.
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1-甲基腺苷、7-甲基鸟苷、乙烯腺苷及其质子化盐的比较结构分析 IV：天然同位素丰度的 1H、13C 和 15N NMR 研究。
DOI：
10.1093/nar/14.19.7783
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发表时间：
1986
影响因子：
14.9
通讯作者：
Agris,PF
中科院分区：
文献类型：
--
作者：
Sierzputowska-Gracz,H;Gopal,HD;Agris,PF
本文分析了核苷1-甲基腺苷（m1A）、7-甲基鸟苷（m7 G）和乙烯基腺苷（EA）的中性和质子化形式的~ 1H、~（13）C、~（15）N NMR谱，以确定m1A和m7 G的质子化位点。这些核苷的质子化发生在m1A和EA的嘧啶环和m7 G的咪唑环中，电荷分布而不是局部化。在溶液中观察到mA和MG的结构差异，并与那些存在于晶体状态的单体，以及在tRNA这些核苷经常发生比较。质子化的核苷结构在溶液中的糖折叠和糖苷键构象与x射线晶体学数据相比是有利的。质子化monoclonsides的甲基基团碳化学位移对应于那些在天然tRNA结构中的相应核苷的甲基。因此，tRNA甲基碳化学位移指示核酸的天然三维结构中的完全质子化的核苷。
The1H,13C,15and N NMR spectra of neutral and protonated forms of the nucleosides 1-methyladenosine (m1A), 7-methylguanosine (m7G) and ethenoadenosine (EA), as a model compound, have been analyzed in order to assign the site of protonation in m1A and m7G. Protonation of these nucleosides occurs in the pyrimidine ring of m1A and EA and in the imidazole ring of m7G, with the charge being distributed rather than localized. Structural differences for both mA and mG were observed in solution and compared with those existing in the crystal state of monomers as well as in tRNA where these nucleosides occur quite often. The protonated nucleoside structures in solution compared favorably in sugar pucker and glycosidic bond conformations with x-ray crystallographic data. Methyl group carbon chemical shifts of the protonated mononucleosides corresponded to those of the methyls of the respective nucleosides in native tRNA structures. Therefore, the tRNA methyl group carbon chemical shifts are indicative of fully protonated nucleosides in the native, three dimensional structure of the nucleic acid.