Structural effect of nucleotides on syn-anti glycosyl isomerization kinetics by ultrasonic relaxation methods

Above pH 12, a single ultrasonic relaxation absorption was observed at 100 MHz, while two relaxational frequencies were observed near pH 7 in 5'-GMP a queous solutions. The single relaxation observed above pH 12 was attributed to a perturbation of the syn-anti rotational isomerization around the glyc osyl bond based on the concentration and pH dependence of the relaxation fr equency and the maximum absorption per wavelength. The kinetic and thermody namic parameters were determined for the isomerization reaction. The result s for the isomerization around the glycosyl bond in 5'-GMP are compared to those reported on related systems, and from such a comparison the effects o f structural changes on the dynamics of syn-anti isomerization can be deduc ed.