title: [Oligonucleotides and their analogs. III. Circular dichroism and conformation of analogs cytidylyl-(3'--5')-adenosine].
abstract: The CD spectra of 11 analogues of CpA, containing modified carbohydrate residue, achiral hydroxyalkyl- and optically active hydroxymethylene substituents have been studied. On the basis of the dependence of the CD spectra on temperature, the constants of U in equilibrium S equilibria and thermodynamic parameters in the approximation of dilute solution was calculated. The calculation was carried out on a computer in the terms of a two-state model. The influence of the modifications of the carbohydrate on the stability of the S-conformation is discussed. The CD spectra of S-conformation was calculated and the assumption of the origin of oligonucleotides CD is considered. Possible mechanisms of how water participates in the stabilization of the S-conformation of dinucleoside phosphate are analyzed.
mesh_terms: D000241:Adenosine; D002942:Circular Dichroism; D003568:Cytidine Monophosphate; D008956:Models, Chemical; D008968:Molecular Conformation; D009841:Oligonucleotides; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D009841:Oligonucleotides; D003568:Cytidine Monophosphate; D000241:Adenosine
vernacular_title: Oligonukleotidy i ikh analogi. III. Krugovoĭ dikhroizm i konformatsiia analogov tsitidilil-(3'--5')-adenozina.