Cooperative aspects of small ion, small molecule interactions with nucleic aicds. Potassium-polyriboadenylic acid, polyribouridylic acid.
Ionic conductivity measurements vs. temperature were made on KCl solutions of K-polyriboadenylic acid + K-polyribouridylic acid (K-poly-A + K-poly-U) in regions of temperature and composition where the helix-coil transition occurred. It was possible to relate the measurements to a differential helix-to-coil binding of K(+) to nucleotide. The results were, within experimental error, the same as those obtained from a limited number of differential KCl activity coefficient measurements and from a theoretical interpretation of polymer free-boundary electrophoretic mobilities. It was concluded that the alkali ion-phosphate interaction in polynucleotides must be regarded as cooperative in nature and several criteria for recognition of such phenomena were given. A brief outline for a proposed statistical mechanical model for binding was presented.
D000227:Adenine Nucleotides; D004553:Electric Conductivity; D004586:Electrophoresis; D008962:Models, Theoretical; D009696:Nucleic Acids; D011188:Potassium; D014500:Uracil Nucleotides
D000227:Adenine Nucleotides; D009696:Nucleic Acids; D014500:Uracil Nucleotides; D011188:Potassium