title: Phosphorylation of carbovir enantiomers by cellular enzymes determines the stereoselectivity of antiviral activity.
abstract: Two enantiomers of carbovir, a carbocyclic analog of 2',3'-dideoxyguanosine, were compared with respect to their phosphorylation and the phosphorylation of their nucleotides by mammalian enzymes. 5'-Nucleotidase catalyzed the phosphorylation of (-)-carbovir, which is active against HIV (human immunodeficiency virus), but did not phosphorylate (+)-carbovir. (-)-Carbovir monophosphate was 7,000 times more efficient as a substrate for GMP kinase than was (+)-carbovir monophosphate. Pyruvate kinase, phosphoglycerate kinase, and creatine kinase phosphorylated both enantiomers of carbovir diphosphate at similar rates. Nucleoside-diphosphate kinase preferentially phosphorylated the (-)-enantiomer. Both enantiomers of carbovir triphosphate were substrates and alternative substrate inhibitors of HIV reverse transcriptase. Thus, the contrasting HIV-inhibitory activities of carbovir enantiomers were due to differential phosphorylation by cellular enzymes and not due to enantioselectivity of HIV reverse transcriptase.
authors.affiliation: Division of Experimental Therapy, Wellcome Research Laboratories, Research Triangle Park, North Carolina 27709.
authors.forename: W H
authors.initials: WH
authors.lastname: Miller
authors.forename: S M
authors.initials: SM
authors.lastname: Daluge
authors.forename: E P
authors.initials: EP
authors.lastname: Garvey
authors.forename: S
authors.initials: S
authors.lastname: Hopkins
authors.forename: J E
authors.initials: JE
authors.lastname: Reardon
authors.forename: F L
authors.initials: FL
authors.lastname: Boyd
authors.forename: R L
authors.initials: RL
authors.lastname: Miller
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D003402:Creatine Kinase / Q000378:metabolism; D003848:Deoxyguanine Nucleotides / Q000378:metabolism / Q000494:pharmacology; D015224:Dideoxynucleosides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D051528:Guanylate Kinases; D006678:HIV / Q000187:drug effects* / Q000201:enzymology; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009703:Nucleoside-Phosphate Kinase / Q000378:metabolism; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000378:metabolism; D010735:Phosphoglycerate Kinase / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000378:metabolism; D018894:Reverse Transcriptase Inhibitors; D013237:Stereoisomerism; D013698:Templates, Genetic; D006160:Guanosine Triphosphate
chemical_list: D000998:Antiviral Agents; D003402:Creatine Kinase; D003848:Deoxyguanine Nucleotides; D015224:Dideoxynucleosides; D051528:Guanylate Kinases; D009703:Nucleoside-Phosphate Kinase; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D010735:Phosphoglycerate Kinase; D010770:Phosphotransferases; D011770:Pyruvate Kinase; D018894:Reverse Transcriptase Inhibitors; C057503:carbovir; C066928:carbovir triphosphate; D006160:Guanosine Triphosphate