Orr D C, Figueiredo H T, Mo C L, Penn C R, Cameron J M
Department of Virology, Glaxo Group Research Ltd., Greenford, United Kingdom.
J Biol Chem. 1992 Feb 25;267(6):4177-82.
Carbocyclic 2',3'-didehydro-2',3'-dideoxyguanosine (carbovir, NSC 614846) is an anti-retroviral agent that may be useful in the treatment of AIDS. We have examined the ability of (-)-enantiomeric carbovir triphosphate to inhibit human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (EC 2.7.7.49). A comparison of inhibition kinetics was made with 3'-azido-2',3'-dideoxythymidine triphosphate and phosphonoformate. Inhibition of the reverse transcriptase was evaluated using poly(rA).oligo(dT)12-18, poly(rC).oligo(dG)12-18, or influenza virion RNA template with a specific oligodeoxynucleotide as primer. (-)-Carbovir 5'-triphosphate was shown to be a potent inhibitor of HIV-1 reverse transcriptase with an apparent Ki similar to that of 3'-azido-2',3'-dideoxythymidine triphosphate. Chain elongation studies utilizing an MS2 RNA template showed that (-)-carbovir 5'-triphosphate terminated transcription at positions identical to those where dideoxy-GTP terminated. This indicates that (-)-carbovir 5'-monophosphate is incorporated into the newly synthesized DNA and terminates transcription at that point. We conclude that (-)-carbovir 5'-triphosphate is a potent inhibitor of the HIV-1 reverse transcriptase enzyme and that (-)-carbovir most likely inhibits HIV by activity at the triphosphate level by a combination of direct competition for binding of the natural deoxynucleoside triphosphates to the reverse transcriptase and chain termination.
碳环2'，3'-二脱氢-2'，3'-二脱氧鸟苷（卡波韦，NSC 614846）是一种抗逆转录病毒药物，可能对治疗艾滋病有用。我们研究了（-）-对映体卡波韦三磷酸抑制人类免疫缺陷病毒1型（HIV-1）逆转录酶（EC 2.7.7.49）的能力。将抑制动力学与3'-叠氮基-2'，3'-二脱氧胸苷三磷酸和膦甲酸进行了比较。使用聚（rA）·寡聚（dT）12-18、聚（rC）·寡聚（dG）12-18或流感病毒粒子RNA模板与特定的寡脱氧核苷酸作为引物来评估逆转录酶的抑制作用。（-）-卡波韦5'-三磷酸被证明是HIV-1逆转录酶的有效抑制剂，其表观Ki与3'-叠氮基-2'，3'-二脱氧胸苷三磷酸相似。利用MS2 RNA模板进行的链延伸研究表明，（-）-卡波韦5'-三磷酸在与双脱氧GTP终止转录的相同位置终止转录。这表明（-）-卡波韦5'-单磷酸被掺入新合成的DNA中并在该点终止转录。我们得出结论，（-）-卡波韦5'-三磷酸是HIV-1逆转录酶的有效抑制剂，并且（-）-卡波韦最有可能通过在三磷酸水平上的活性，通过直接竞争天然脱氧核苷三磷酸与逆转录酶的结合以及链终止的组合来抑制HIV。
