DNA-like duplexes with repetitions. I. Properties of concatemer duplexes formed by d(T-G-C-A-C-A-T-G).
A new class of synthetic DNA duplexes containing repeating oligonucleotide sequences, double-helical concatemers, is characterized. The UV-absorption and circular dichroism of a concatemer formed in self-association of d(T-G-C-A-C-A-T-G) have been studied. The thermodynamical parameters of complex formation are the following: delta Ho1 = -9.2 +/- 0.3 kcal/mol, delta So1 = -27 +/- 1 e.u. The data obtained show that pseudopolymeric duplexes having structures that are similar to DNA-B-type helices are formed in solutions of d(T-G-C-A-C-A-T-G). Polymerization of 32P-d(pT-G-C-A-C-A-T-G) induced by water-soluble carbodiimide has been carried out under the conditions of concatemer stability. The yield of the dimer, a 16-member oligonucleotide, was 13%.
D002234:Carbodiimides; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D004247:DNA / Q000138:chemical synthesis*; D046911:Macromolecular Substances; D009690:Nucleic Acid Conformation; D012091:Repetitive Sequences, Nucleic Acid; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D002234:Carbodiimides; D046911:Macromolecular Substances; D004247:DNA