Conformational, Thermodynamic and Kinetic Studies of RNA-DNA Hydbid Duplexes

这项建议的目的是研究序列和溶液盐浓度如何影响DNA-RNA杂化齐聚物的结构、热力学和动力学性质。需要解决的问题是：DNA-RNA杂交双链是否只以A型螺旋存在，或者它们是否表现出依赖于序列的形状？最近邻序列决定杂交双链稳定性的作用是什么？盐浓度如何影响杂化分子的物理性质和行为？主要工作包括：1.双链杂化构象的圆二向色性研究熔融研究为预测杂化双链在1.0MNa+中的稳定性和构象发展了一套基本的自由能参数。3.光学熔融研究了盐对双链形成热力学的影响。构建了激光拉曼温度跳跃分光光度计，以测量杂交双链形成的动力学特性作为碱基序列和盐浓度的函数。

The objective of this proposal is to study how sequence and solution salt concentration influence the structural, thermodynamic and kinetic properties of a DNA-RNA hybrid oligomer. Questions to be addressed are: Do DNA-RNA hybrid duplexes exist only as A-form helices or do they display a sequence dependent shape?, What is the role of nearest neighbor sequence determining the stability of a hybrid duplex? and How does salt concentration affect the physical properties and behavior of hybrid molecules? Work will include: 1. Circular dichroism studies of hybrid duplex conformation as a function of sequence and salt concentration 2. Optical melting studies to develop a basis set of free energy parameters for the prediction of stability and conformation of hybrid duplexes in 1.0 M Na+ 3. Optical melting studies of the effects of salt on the thermodynamics of duplex formation 4. The construction of a laser Raman temperature jump spectrophotometer to measure kinetic properties of hybrid duplex formation as a function of base sequence and salt concentration.