Pre-steady state kinetic analysis of cyclobutyl derivatives of 2'-deoxyadenosine 5'-triphosphate as inhibitors of HIV-1 reverse transcriptase.

Pre-steady state kinetic analysis was utilized for biochemical evaluation of a series of cyclobutyl adenosine nucleotide analogs with HIV-1 RT(WT). The phosphonyl-diphosphate form of the cyclobutyl nucleotide, 5, was the most efficiently incorporated of the series. Nucleotide 5 was fourfold more efficiently incorporated than the FDA approved TFV-DP by RT(WT). The kinetics of incorporation for 5 using the drug resistant mutant enzyme K65R was also determined. Compound 5 was threefold more efficiently incorporated compared to TFV-DP with RT(K65R). These results demonstrate cyclobutyl adenosine analogs can act as substrates for incorporation by HIV-1 RT and be a potential scaffold for HIV inhibitors.