Barciszewski J, Bratek-Wiewiórowska M D, Górnicki P, Naskret-Barciszewska M, Wiewiórowski M, Zielenkiewicz A, Zielenkiewicz W
Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan.
Nucleic Acids Res. 1988 Jan 25;16(2):685-701. doi: 10.1093/nar/16.2.685.
An attempt has been made to correlate differential scanning calorimetry melting profiles of 5S rRNAs from lupin seeds (L.s.) and wheat germ (W.g.) with their structure. It is suggested that the observed differences in thermal unfolding are due to differences in RNA nucleotide sequence and as a consequence in higher order structures. Interesting effects induced by magnesium cation, perprotonated and permethylated sperminium tetracations are discussed. It is suggested that the difference in the stabilizing effect of the three cations results from different mode of their interactions with RNA. "Pure" electrostatic interactions expected for permethylated tetracations are rather weak due to the steric hindrance around each positively charged nitrogen atom. Electrostatic interactions of the other two cations are significantly enhanced by coordination bonding for magnesium and by hydrogen bonding for protonated sperminium cation.
人们已尝试将羽扇豆种子（L.s.）和小麦胚芽（W.g.）的5S rRNA的差示扫描量热法熔解曲线与其结构相关联。研究表明，观察到的热解链差异是由于RNA核苷酸序列的差异以及由此导致的高级结构差异所致。文中讨论了镁阳离子、全质子化和全甲基化精胺四价阳离子所引发的有趣效应。研究认为，三种阳离子稳定作用的差异源于它们与RNA相互作用方式的不同。由于每个带正电荷的氮原子周围存在空间位阻，全甲基化四价阳离子预期的“纯粹”静电相互作用相当微弱。另外两种阳离子的静电相互作用因镁离子的配位键和质子化精胺阳离子的氢键作用而显著增强。
