Borazan H N, Koumriqian S N
J Pharm Sci. 1983 Dec;72(12):1450-3. doi: 10.1002/jps.2600721220.
A circular dichroism spectropolarimetric study on the conformation of polyadenylic acid (poly A) in neutral solutions demonstrated a coil leads to helix transition induced by intercalative binding of critical amounts of epinephrine, norepinephrine, and isoproterenol relative to poly A. Theoretical treatment of the experimental data indicated a first-order kinetic transition in poly A. It was possible to measure transition rate constants of the epinephrine-poly A and norepinephrine-poly A systems and to calculate the activation energies. The results indicate a high level of temperature dependence of the rate constants. The effects can be reversed by increasing ionic strength, indicating the significance of the electrostatic interactions. The importance of the results is discussed in terms of the possible role of the catecholamines as control mechanisms for the poly A-regulated translation of the genetic code on mRNA.
一项关于中性溶液中聚腺苷酸（poly A）构象的圆二色光谱偏振研究表明，相对于poly A，临界量的肾上腺素、去甲肾上腺素和异丙肾上腺素的嵌入结合会诱导其从卷曲态转变为螺旋态。对实验数据的理论处理表明poly A发生了一级动力学转变。可以测量肾上腺素-poly A和去甲肾上腺素-poly A系统的转变速率常数并计算活化能。结果表明速率常数对温度高度依赖。增加离子强度可使这些效应逆转，这表明静电相互作用的重要性。根据儿茶酚胺作为poly A调节mRNA上遗传密码翻译的控制机制的可能作用，讨论了这些结果的重要性。
