Faraj A, Agrofoglio L A, Wakefield J K, McPherson S, Morrow C D, Gosselin G, Mathe C, Imbach J L, Schinazi R F, Sommadossi J P
Department of Pharmacology, University of Alabama at Birmingham 35294.
Antimicrob Agents Chemother. 1994 Oct;38(10):2300-5. doi: 10.1128/AAC.38.10.2300.
(-)-beta-L-2',3'-Dideoxycytidine (L-ddC) and (-)-beta-L-2',3'-dideoxy-5-fluorocytidine (L-FddC) have been reported to be potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) in vitro. In the present study, the 5'-triphosphates of L-ddC (L-ddCTP) and L-FddC (L-FddCTP) were demonstrated to competitively inhibit HIV-1 reverse transcriptase (RT), with inhibition constants (KiS) of 2 and 1.6 microM, respectively, when a poly(rI).oligo(dC)10-15 template primer was used; in comparison Ki values for beta-D-2',3'-dideoxycytidine 5'-triphosphate (D-ddCTP) and beta-D-2',3'-dideoxy-5-fluorocytidine 5'-triphosphate (D-FddCTP) were 1.1 and 1.4 microM, respectively. Use of the mutant RT at position 184 (substitution of methionine to valine [M184V]), which is associated with resistance to beta-L-2',3'-dideoxy-3'-thiacytidine (3TC) and beta-L-2',3'-dideoxy-5-fluoro-3'-thiacytidine (FTC), resulted in significant increases (50- to 60-fold) in Ki values for L-ddCTP and L-FddCTP, whereas the elevation in Ki values for D-ddCTP and D-FddCTP was moderate (2-fold). L-ddCTP and L-FddCTP did not inhibit human DNA polymerases alpha and beta up to 100 microM. In contrast, D-ddCTP and D-FddCTP inhibited human DNA polymerase beta, with Ki values of 0.5 and 2.5 microM, respectively. By using sequencing analysis, L-ddCTP and L-FddCTP exhibited DNA chain-terminating activities toward the parental HIV-1 RT, whereas they were not a substrate for the mutant M184V HIV-1 RT.L-ddC and L-FddC did not inhibit the mitochondrial DNA content of human cells up to a concentration of 10 microM, whereas D-ddC and D-FddC decreased the mitochondrial DNA content by 90% at concentrations of 1 and 10 microM, respectively. All of these results suggest that further development of L-ddC, and L-FddC in particular, is warranted as a possible anti-HIV candidate.
据报道，（-）-β-L-2'，3'-双脱氧胞苷（L-ddC）和（-）-β-L-2'，3'-双脱氧-5-氟胞苷（L-FddC）在体外是人类免疫缺陷病毒1型（HIV-1）和2型（HIV-2）的有效且选择性抑制剂。在本研究中，当使用聚（rI）·寡聚（dC）10-15模板引物时，L-ddC（L-ddCTP）和L-FddC（L-FddCTP）的5'-三磷酸酯被证明可竞争性抑制HIV-1逆转录酶（RT），抑制常数（KiS）分别为2和1.6微摩尔；相比之下，β-D-2'，3'-双脱氧胞苷5'-三磷酸酯（D-ddCTP）和β-D-2'，3'-双脱氧-5-氟胞苷5'-三磷酸酯（D-FddCTP）的Ki值分别为1.1和1.4微摩尔。使用与对β-L-2'，3'-双脱氧-3'-硫代胞苷（3TC）和β-L-2'，3'-双脱氧-5-氟-3'-硫代胞苷（FTC）耐药相关的184位突变逆转录酶（甲硫氨酸替换为缬氨酸[M184V]），导致L-ddCTP和L-FddCTP的Ki值显著增加（50至60倍），而D-ddCTP和D-FddCTP的Ki值升高幅度适中（2倍）。L-ddCTP和L-FddCTP在高达100微摩尔时不抑制人DNA聚合酶α和β。相比之下，D-ddCTP和D-FddCTP抑制人DNA聚合酶β，Ki值分别为0.5和2.5微摩尔。通过测序分析，L-ddCTP和L-FddCTP对亲本HIV-1 RT表现出DNA链终止活性，而它们不是突变体M184V HIV-1 RT的底物。L-ddC和L-FddC在浓度高达10微摩尔时不抑制人细胞的线粒体DNA含量，而D-ddC和D-FddC在浓度分别为1和10微摩尔时使线粒体DNA含量降低90%。所有这些结果表明，L-ddC，特别是L-FddC，作为一种可能的抗HIV候选药物值得进一步开发。
