title: Hydrogen bonding abilities of 2,4-dithiouridine derivatives.
abstract: The base pairing ability of a di-2,4-thiouridine derivative was studied in carbon tetrachloride solutions by the methods of infrared spectroscopy. The strength of the association by hydrogen bonding was found to decrease in the following order: adenine-uracil, adenine-di-2,4-thiouracil, uracil-uracil, and di-2,4-thiouracil-di-2,4-thiouracil. These findings contrast with the previously demonstrated fact that poly(s2s4U) is strongly self-associated and does not form a complex with poly(A). To correlate these results, it is proposed that long range stabilizing forces are acting between the di-2,4-thiouracil residues in polynucleotide chains. This assumption also explains the existence of an ordered structure in the alternating copolymer poly(s2s4U-A).
mesh_terms: D000227:Adenine Nucleotides; D002251:Carbon Tetrachloride; D055598:Chemical Phenomena; D002621:Chemistry; D006859:Hydrogen; D009690:Nucleic Acid Conformation; D011063:Poly A-U; D011072:Poly U; D011119:Polynucleotides; D013055:Spectrophotometry, Infrared; D013891:Thiouridine / Q000031:analogs & derivatives*
chemical_list: D000227:Adenine Nucleotides; D011119:Polynucleotides; D013891:Thiouridine; D011063:Poly A-U; D011072:Poly U; D006859:Hydrogen; D002251:Carbon Tetrachloride