Extensive circular dichroism studies have been conducted with the title polynucleotides under various solution conditions. The studies provided the following information: (i) The halogen atoms in place of thymine methyl hinder the isomerization into X-DNA. (ii) The brominated but not iodinated polynucleotide isomerizes into Z-DNA in concentrated NaCl+NiCl2. The transition takes place at lower NiCl2 concentrations than with poly(dA-dT). (iii) The iodinated polynucleotide forms an unusual conformation in aqueous solution in which it is very stable. It isomerizes from this conformer into the usual B-type double helix in concentrated ethanol solutions. The isomerization is a two-state cooperative process. (iv) Both title polynucleotides undergo still another two-state cooperative transition in trifluorethanol solutions presumably into A-DNA showing a rather unusual circular dichroism spectrum.

Institute of Biophysics Czechoslovak Academy of Sciences Brno

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Proc Natl Acad Sci U S A. 1979 Jun;76(6):2508-11 PubMed

J Mol Biol. 1963 Nov;7:511-26 PubMed

J Biol Chem. 1991 Apr 5;266(10):6106-12 PubMed

Nucleic Acids Res. 1991 May 11;19(9):2343-7 PubMed

Biochem Biophys Res Commun. 1985 Oct 15;132(1):95-9 PubMed

J Biomol Struct Dyn. 1987 Dec;5(3):639-50 PubMed

Biochemistry. 1986 Jul 15;25(14):3995-4007 PubMed

J Biomol Struct Dyn. 1985 Aug;3(1):43-55 PubMed

Biochem Biophys Res Commun. 1971 Dec 17;45(6):1542-7 PubMed

Nucleic Acids Res. 1983 Apr 25;11(8):2495-510 PubMed

J Mol Biol. 1983 May 5;166(1):85-92 PubMed

Biochemistry. 1981 May 26;20(11):3049-55 PubMed

J Mol Biol. 1962 Aug;5:185-200 PubMed

J Mol Biol. 1979 Jul 15;131(4):669-80 PubMed

Nature. 1978 Jun 22;273(5664):687-8 PubMed

Biochim Biophys Acta. 1976 May 3;432(2):185-91 PubMed

J Mol Biol. 1991 Jan 5;217(1):177-99 PubMed

Gen Physiol Biophys. 1990 Aug;9(4):415-8 PubMed

J Biomol Struct Dyn. 1990 Jun;7(6):1211-20 PubMed

J Biomol Struct Dyn. 1989 Feb;6(4):715-27 PubMed

Biochemistry. 1988 Mar 8;27(5):1729-35 PubMed

Biochemistry. 1986 Jun 3;25(11):3220-5 PubMed

Bioessays. 1985 Dec;3(6):245-8 PubMed

J Biomol Struct Dyn. 1985 Aug;3(1):67-83 PubMed

Biochim Biophys Acta. 1985 Feb 15;838(2):244-51 PubMed

Biochem Biophys Res Commun. 1980 Jul 16;95(1):156-62 PubMed

J Biomol Struct Dyn. 1983 Oct;1(1):21-57 PubMed

Biochemistry. 1982 Oct 26;21(22):5463-7 PubMed

Nucleic Acids Res. 1982 Nov 11;10(21):6969-79 PubMed

J Mol Biol. 1962 Aug;5:172-84 PubMed

J Mol Biol. 1962 Aug;5:201-16 PubMed

Biopolymers. 1990 Feb 5;29(2):385-92 PubMed

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