论文标题
Mg2+离子对由多迪比迪迪伯丝链形成的双链孢子核苷酸的稳定性的影响
Mg2+ ion effect on stability of double-stranded popynucleotide formed by polyriboinosinic and polyribocytidilic chains
论文作者
论文摘要
MG2+对接近生理生理的条件（0.1M Na+，pH7）的双链多核苷酸聚丙烯（IC）的热稳定性的影响通过差异紫外线光谱研究了。离子浓度（[MG2+]）的初始增加导致熔融温度（TM）的升高，并导致螺旋线圈转变（HMAX）引起的吸收高染料值的降低。 MG2+相互作用与低黄嘌呤或胞嘧啶环的P电子（阳离子-P相互作用）相互作用。当[Mg2+]达到约10-4 m的临界值时，TM降低，HMAX增加到在没有镁的情况下接近一个值的值。据推测，在[mg2+] = [mg2+] cr ic转移到新的结构状态。随着[Mg2+> [Mg2+]，Cr TM再次增加，Hmax慢慢降低。关键词：多核苷酸，热稳定性，金属离子。
Mg2+ effect on the thermal stability of the double-stranded polynucleotide polyIpolyC (IC) under conditions close to physiological ones (0.1M Na+, pH7) was studied by the differential UV spectroscopy. The initial increase of the ion concentration ([Mg2+]) leads to the increase of the melting temperature (Tm) and to the decrease of the absorption hyperchromicity value that is caused by the helix-coil transition (hmax). Mg2+ interacts to p-electrons of hypoxanthine or cytosine rings (cation-p-interaction). When [Mg2+] reaches a critical value of about 10-4 M, Tm decreases and hmax increase to values close to one observed in the absence of magnesium. It is supposed that at [Mg2+]=[Mg2+]cr IC transits into a new structural state. With [Mg2+>[Mg2+]cr Tm increases again and hmax slowly decreases. Key words: polynucleotides, thermal stability, metal ions.
