Poster abstracts

Poster number 8 submitted by Jenee Cyran

NMR Structure Predictions of Hexamer and Tetramer Oligo (C)

Jenee D. Cyran (Department of Chemistry, Allegheny College), Jason Tubbs (Department of Chemistry, University of Rochester), Douglas H. Turner (Department of Chemistry, University of Rochester), Marty Serra (Department of Chemistry, Allegheny College)

Abstract:
Various two-dimensional proton NMR experiments have been completed to determine the structure of the hexamer r(C6) and tetramer r(C4) . One-dimensional variable temperature experiments determined the optimum temperature for two-dimensional experiments; the temperature with the fewest overlapping peaks is 25^oC. Two-dimensional experiments were also done at 0^oC to lower proton exchange. The NOESY experiments allow the order of nucleotides in r(C6) to begin to be determined from the NOESY walk. The relative distance between H6 to H5, H5 to H1’, and H6 to H1’ can be observed in the 2D NOESY experiments. These spectra illustrated that H5 appears be closer to H6 than it is to it’s H1’ in C6. The distance between H6 and H5 is known to be 2.4 Ao, and from the relative size of the cross peaks is found to be the shortest distance between H’s of the three examples. These results differ from the previous study (1) of a poly(C) which showed the H5 to H1’ to be the strongest cross peak suggesting that the H5 to H1’ distance less than 2.4 Ao. Molecular modeling of the hexamer C will be performed once the NOESY walk is finished and the NOE cross-peak volumes are computed. Future projects will help determine the solution structure of single stranded hexamer and tetramer C.

Keywords: NMR, Hexamer C and Tetramer C, Oligo (C)