The molecular mechanism of multidrug resistance by the Q151M human immunodeficiency virus type 1 reverse transcriptase and its suppression using alpha-boranophosphate nucleotide analogues.
Nucleoside analogues are currently used to treat human immunodeficiency virus infections. The appearance of up to five substitutions (A62V, V75I, F77L, F116Y, and Q151M) in the viral reverse transcriptase promotes resistance to these drugs, and reduces efficiency of the antiretroviral chemotherapy. Using pre-steady state kinetics, we show that Q151M and A62V/V75I/F77L/F116Y/Q151M substitutions confer to reverse transcriptase (RT) the ability to discriminate an analogue relative to its natural counterpart, and have no effect on repair of the analogue-terminated DNA primer. Discrimination results from a selective decrease of the catalytic rate constant k(pol): 18-fold (from 7 to 0.3 s(-1)), 13-fold (from 1.9 to 0.14 s(-1)), and 12-fold (from 13 to 1 s(-1)) in the case of ddATP, ddCTP, and 3'-azido-3'-deoxythymidine 5'-triphosphate (AZTTP), respectively. The binding affinities of the triphosphate analogues for RT remain unchanged. Molecular modeling explains drug resistance by a selective loss of electrostatic interactions between the analogue and RT. Resistance was overcome using alpha-boranophosphate nucleotide analogues. Using A62V/V75I/F77L/F116Y/Q151M RT, k(pol) increases up to 70- and 13-fold using alpha-boranophosphate-ddATP and alpha-boranophosphate AZTTP, respectively. These results highlight the general capacity of such analogues to circumvent multidrug resistance when RT-mediated nucleotide resistance originates from the selective decrease of the catalytic rate constant k(pol).
Centre National de la Recherche Scientifique and Universités d'Aix-Marseille I et II, UMR 6098, Architecture et Fonction des Macromolécules Biologiques, ESIL-Case 925, 163 avenue de Luminy, 13288 Marseille cedex 9, France.
Jerome
J
Deval
Boulbaba
B
Selmi
Joelle
J
Boretto
Marie Pierre
MP
Egloff
Catherine
C
Guerreiro
Simon
S
Sarfati
Bruno
B
Canard
D019380:Anti-HIV Agents / Q000494:pharmacology*; D003838:Deoxyadenine Nucleotides / Q000494:pharmacology; D054306:Dideoxynucleotides; D018432:Drug Resistance, Multiple; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors / Q000235:genetics*; D008958:Models, Molecular; D009154:Mutation; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D013942:Thymine Nucleotides / Q000494:pharmacology*; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000494:pharmacology*
D019380:Anti-HIV Agents; D003838:Deoxyadenine Nucleotides; D054306:Dideoxynucleotides; D018894:Reverse Transcriptase Inhibitors; D013942:Thymine Nucleotides; C037773:2',3'-dideoxyadenosine triphosphate; D015215:Zidovudine; C052873:zidovudine triphosphate; D054303:HIV Reverse Transcriptase