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Nuclear magnetic resonance and circular dichroism studies of a duplex--single-stranded hairpin loop equilibrium for the oligodeoxyribonucleotide sequence d(CGCGATTCGCG).
- Source :
-
Nucleic acids research [Nucleic Acids Res] 1985 Sep 11; Vol. 13 (17), pp. 6375-86. - Publication Year :
- 1985
-
Abstract
- Nuclear magnetic resonance (NMR) and circular dichroism (CD) studies have been carried out with the oligodeoxyribonucleotide mismatch sequence, d(CGCGATTCGCG), 1. It has been found that 1 exists, in solution, as an equilibrium mixture of slowly interconverting, structured conformational isomers, 1a and 1b. On the basis of the concentration dependence of the 1a-1b equilibrium, the 1H NMR spectrum of the imino protons of the nucleotide bases, and the individual CD spectra of 1a and 1b, it is suggested that the two species correspond to a B-type DNA duplex and a single-stranded, hairpin-loop structure; the portion of the single-stranded species not involved in the loop appears to have a B-type DNA structure (on the basis of the CD measurements). To facilitate 1H NMR resonance assignments, the two possible des-methyl thymidine derivatives of 1 were synthesized; the effect of this substitution on the physical chemical properties of 1 was explored. The 1H NMR spectra of 1, as a function of temperature, showed that, under conditions wherein both species were present to a significant extent, the duplex form melted at a lower temperature than the single-stranded, hairpin loop structure.
Details
- Language :
- English
- ISSN :
- 0305-1048
- Volume :
- 13
- Issue :
- 17
- Database :
- MEDLINE
- Journal :
- Nucleic acids research
- Publication Type :
- Academic Journal
- Accession number :
- 4047943
- Full Text :
- https://doi.org/10.1093/nar/13.17.6375