Two-dimensional sup 1 H and sup 31 P NMR spectra and restrained molecular dynamics structure of a mismatched GA decamer oligodeoxyribonucleotide duplex
- Purdue Univ., West Lafayette, IN (USA)
Assignment of the {sup 1}H and {sup 31}P NMR spectra of a tandem G{center dot}A mismatched base pair decamer oligodeoxyribonucleotide duplex, d(CCAAGATTGG){sub 2}, has been made by two-dimensional {sup 1}H-{sup 1}H and heteronuclear {sup 31}P-{sup 1}H correlated spectroscopy. Unusual downfield {sup 31}P resonances have been assigned by a pure absorption phase constant-time heteronuclear {sup 31}P-{sup 1}H correlated spectrum to be associated with the phosphates on the 5{prime}- and 3{prime}-sides of the mismatched guanosine residue. J{sub H3{prime}-P} coupling constants for each of the phosphates of the decamer were obtained from the {sup 1}H-{sup 31}P J-resolved selective proton-flip 2D spectrum. The two most downfield-shifted {sup 31}P resonances each appear to consist of two overlapping signals that can be resolved into two distinct doublets with different coupling constants in the J-resolved spectrum. This as well as the temperature dependence of the {sup 31}P spectra demonstrates that two distinct conformations exist at lower temperatures. By use of a modified Karplus relationship, the C4{prime}-C3{prime}-O3{prime}-P torsional angles ({epsilon}) were obtained. A linear correlation between {sup 31}P chemical shifts and the measured coupling constants is quite good. The {sup 31}P chemical shifts as well as the measured coupling constants tend to follow the positional variation seen in other duplexes of interior phosphates resonating more upfield than terminal residues.
- OSTI ID:
- 5706670
- Journal Information:
- Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:37; ISSN 0006-2960; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ADENINES
AMINES
ANTIMETABOLITES
AROMATICS
AZAARENES
BARYONS
CHEMICAL SHIFT
CONFORMATIONAL CHANGES
DNA MISMATCH
DRUGS
ELEMENTARY PARTICLES
FERMIONS
GUANINE
HADRONS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
NUCLEIC ACIDS
NUCLEONS
ODD-EVEN NUCLEI
OLIGONUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
PROTONS
PURINES
SPECTRA
STABLE ISOTOPES
TEMPERATURE DEPENDENCE