Che-Hung Lee

300 MHz NMR study on the effect of base stacking on backbone conformational flexibility in oxy- and deoxy- adenyl dinucleosides

Summary The 300 MHz 1 H and 40.48 MHz 31 P NMR spectra of ApA, dApdA, and several purine nucleotides in aqueous solution have been completely analyzed at various temperatures or concentrations, and the derived coupling constant data interpreted in terms of dynamic conformational parameters by means of a Karplustype analysis. It is found that base stacking interactions play a key role in reducing conformational flexibility. The C(4′)-C(5′) and C(5′)-o(5′) bonds in both oxy- and deoxy- adenyl dinucleosides become increasingly gauche conformation with increasing base stacking, while the ribose ring in ApA correspondingly becomes more 3 E conformation and the deoxyribose ring in dApdA remains mostly 2 E conformation.

Complete analysis of the fast fourier transformed 1HNMR spectra of coenzyme A, acetyl coenzyme A and 3′5′ ADP and their solution conformation

‘Coenzyme A is the most prominent acyl group transfer coenzymes in living systems. Its universal occurrence, the large number of enzymatic reactions in which it is involved, and the variety of reaction types in which its derivatives are concerned testify to its importance’ [ 11. Since its discovery and elucidation of its primary structure [2,3], nothing is known up to the present time, with respect to its conformation. In the present paper, we present for the first time, the complete analysis of the complex ’ HNMR Fourier transformed spectra of coenzyme A (see fig. 1 for structure) and acetyl coenzyme A. Also presented is the complete analysis of the 3’5’ADP spectra which is a component of these coenzymes as well as that of RNA. The NMR data in turn is used to arrive at their time averaged dynamic conformation in aqueous solutions.

1H, 1H-{31P}, 31P, and 31P-{1H} fast fourier transform NMR study of the solution conformation of the cofactors involved in glycogen synthesis: Adenosinediphosphoglucose and uridinediphosphoglucose

Spectra of the component monomeric units ADP, UDP and cY-glucose-l’-phosphate and the cofactors ADPG and UDPG (commercial products) 0.1 M, 30°C in D20 were obtained using a 220 MHz, continuous wave and a 100 MHz fast Fourier transform system. In the 100 MHz system, spectra were taken in both ‘H and 1H-{31P} modes. 31P and 31P{lH} spectra were recorded in the Fourier mode at a frequency of 40.48 MHz. Details of instrumentation are described elsewhere [ 1,2]. The pH of the solution for ADP, UDP and a-glucose-1’-phosphate were respectively