Determination of the DNA sugar pucker using 13C NMR spectroscopy.
Solid-state 13C NMR spectroscopy of a series of crystalline nucleosides and nucleotides allows direct measurement of the effect of the deoxyribose ring conformation on the carbon chemical shift. It is found that 3'-endo conformers have 3' and 5' chemical shifts significantly (5-10 ppm) upfield of comparable 3'-exo and 2'-endo conformers. The latter two conformers may be distinguished by smaller but still significant differences in the carbon chemical shifts at the C-2' and C-4' positions. High-resolution solid-state NMR of three modifications of fibrous calf thymus DNA shows that these trends are maintained in high-molecular-weight DNA and confirms that the major ring pucker in A-DNA is 3'-endo, while both B-DNA and C-DNA are largely 2'-endo. The data show that 13C NMR spectroscopy is a straightforward and useful probe of DNA ring pucker in both solution and the solid state.
Santos
R A
RA
Department of Chemistry, State University of New York, Stony Brook 11794.
Tang
P
P
Harbison
G S
GS
D000818:Animals; D002417:Cattle; D004247:DNA; D003839:Deoxyadenosines; D003841:Deoxycytidine; D003855:Deoxyribose; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation
D003839:Deoxyadenosines; D003841:Deoxycytidine; D003855:Deoxyribose; D004247:DNA