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PubMed · 7946072

Parallel-stranded DNA with mixed sequence. Evidence for conformational transition in solution at low water activity.

A K Shchyolkina·O F Borisova·B K Chernov·N A Tchurikov
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Abstract

Parallel-stranded deoxyoligonucleotide 5'd(CTATAGGGAT)3'/5'd(GATATCCCTA)3' (I-II) was shown to be stable in solution at 3 degrees-5 degrees C, 0.1-0.25 M NaCl, 10(-2) M phosphate buffer, pH 7.0 by means of a set of fluorescent techniques as well as of conventional optical methods. A cooperative change in the CD spectra is observed in trifluoroethanol (TFE) solutions at decreased water activity (relative humidity, r.h.). This distinctive change is supposed to stem from a cooperative conformational transition of parallel double helix from a B-like form with C2' endo sugar conformation to an A-like form designated as Ap. The free energy difference between the Ap and B-like conformation for the parallel duplex is 7.35 kcal/mol which is close to the value 7.40 kcal/mol for the antiparallel 5'd(CTATAGGGAT)3'/3'd(GATATCCCTA)5' (I-III). The ability of parallel helix to transit into Ap form is important for DNA-RNA parallel double helix formation.

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Base CompositionBase SequenceDNAEthidiumMolecular Sequence DataNucleic Acid ConformationOligodeoxyribonucleotidesSolubilityThermodynamicsTrifluoroethanolWaterJournal ArticleResearch Support, Non-U.S. Gov't

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A K Shchyolkina, O F Borisova, B K Chernov, N A Tchurikov. 1994. Parallel-stranded DNA with mixed sequence. Evidence for conformational transition in solution at low water activity.. https://doi.org/10.1080/07391102.1994.10508066

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