The investigation of the solution structure of duplex d(pTGTTTGGC)d(CCAAAC)A by means of one- and two-dimensional 1H NMR spectroscopy and by restrained molecular mechanics

E. V. Bichencova, Yu. N. Vorob'ev, I. V. Kutyavin, A. V. Lebedev, T. V. Maltseva, E. Yu. Tenne

Novosibirsk Institute of Bioorganic Chemistry, Siberian Division, Academy of Sciences of the USSR

Abstract: Structure of the complementary complex d(pTGTTTGGC) d(pCCAAAC)A in the aqueous solution has been investigated by one- and two-dimensional 1H NMR spectroscopy. The resonances of nonexchangeable protons of bases as well as methyl and deo-xyribose 1', 2'a, 2'b, 3' and 4' protons have been assigned by means of two-dimensional J-correlated spectroscopy (COSY) and two-dimensional nuclear Overhauser enhancement spectroscopy (NOESY).Using one-dimensional NOE measurements, 62 interproton distances (intra-nucleotide: (H6/H8)i (H1')i (H6/H8)i (H2'a)i, (HI'); (H2'a),,r(Hl')j (H2'b),; inter-nucleotide: (H6/H8)i-'(Hi')i_1, (H6/H8)i (H2'a)i.1, (H6/H8); - (H2'b)i_1, (H5/CH3)i-(H6/H8)i_v (HS/CHg); (H2'a/H2'b)i_1) have been determined for nearest-neighbour protons.

Spin-coupling constant values for some sugar protons have been obtained from COSY spectra. The restrained molecular mechanics calculations have yielded the possible solution structures of duplex fitting the experimental set of interproton distances and coupling constants.

Russian Journal of Bioorganic Chemistry 1990, 16 (9):1236-1258

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