Solid-state and solution conformation of 3'-amino-3'-deoxythymidine, precursor to a noncompetitive inhibitor of HIV-1 reverse transcriptase.
The recent finding that 3'-amino-3'-deoxythymidine 5'-triphosphate is a noncompetitive inhibitor of the HIV-1 reverse transcriptase (Kedar, P.S.; et al. Biochemistry 1990, 29, 3603-3611), prompted an investigation of the conformation of 3'-amino-3'-deoxythymidine. An X-ray diffraction study has revealed that the glycosidic torsion angle of the nucleoside is in the less common syn region and this solid-state geometry is stabilized by a three-dimensional network of self-associated hydrogen-bonded molecules. On the other hand, the aqueous solution conformation, as determined by 1H NMR, places the glycosidic torsion angle in the more usual anti region with the sugar in an equilibrium between C3'-endo and C2'-endo puckering. The energy barrier between the solid-state and solution conformation is relatively low as was demonstrated by the MM2 calculations.
Kovács
T
T
Biomedical Chemistry Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Párkányi
L
L
Pelczer
I
I
Cervantes-Lee
F
F
Pannell
K H
KH
Torrence
P F
PF
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D015224:Dideoxynucleosides / Q000737:chemistry*; D015497:HIV-1 / Q000201:enzymology*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D018894:Reverse Transcriptase Inhibitors; D012996:Solutions; D014961:X-Ray Diffraction
D015224:Dideoxynucleosides; D018894:Reverse Transcriptase Inhibitors; D012996:Solutions; C019252:3'-aminothymidine