Base interactions of nucleotide polymers in aqueous solution.

摘要: The stability and optical properties of single-strand polynucleotide helices have been investigated, using poly N 6 -hydroxyethyladenylic acid diadenylic as model polymers. In both cases simple hydrogen-bonded base pairing is excluded; nevertheless, the circular dichroic are markedly similar to those neutral pH form polyadenylic acid. consistent with theoretical predictions from a sterically reasonable “stacked base” structure. Thermodynamic analysis its thermal “melting”, demonstrated by dichroism changes, gives standard state enthalpy change +8 kcal./mole ΔF ° about +1 at 0°C. It concluded that acid, A all possess low temperatures ordered structures involving stacking bases. absence complementarity, nucleic acids well such homopolynucleotides should be able assume helical conformation under appropriate conditions.