SYNTHESIS, CHARACTERIZATION, AND INHIBITORY ACTIVITIES OF NUCLEOSIDE ALPHA,BETA-IMIDO TRIPHOSPHATE ANALOGS ON HUMAN IMMUNODEFICIENCY VIRUS-1 REVERSE-TRANSCRIPTASE

Six deoxynucleoside triphosphate (dNTP) analogues were synthesized, ha ving the alpha,beta-P-O-P bond replaced with an imido (P-N-P) function ality. They were all shown to be reasonably potent inhibitors of human immunodeficiency virus-1 reverse transcriptase (HIV-1 RT). This has p ermitted, for the first time, an estimate of the relative binding affi nities of the parent triphosphates (dATP, TTP, dGTP, and dCTP) toward the enzyme's active site, in that they can be compared indirectly by c orrelation with the behavior of their alpha,beta-imido analogues. Othe r complicating processes such as consecutive incorporation into the gr owing DNA chain can be excluded because the imido linkage cannot be cl eaved by HIV-1 RT. The 5-iodo analog of deoxyuridine triphosphate (IdU MPNPP, 5) was the most potent inhibitor, having an IC50 value of 7 mu M. A general route for the phosphorylation of purine and pyrimidine 5' -imidodiphosphates by pyruvate kinase was developed using phosphoenolp yruvate (PEP) as a phosphoryl group donor. Enzymatic phosphorylation w as shown to be a more efficient approach than chemical methods. (C) 19 96 Academic Press, Inc.