A proline-to-histidine substitution at position 225 of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) sensitizes HIV-1 RT to BHAP U-90152.

Abstract

Two mutant virus strains in which the novel P225H mutation appeared in a V106A reverse transcriptase (RT)-mutated genetic background upon treatment of human immunodeficiency virus type 1 (HIV-1) with quinoxaline S-2720 were isolated. Surprisingly, the addition of the P225H mutation to the V106A RT mutant genetic background resensitized the V106A RT mutant virus to the nonnucleoside RT inhibitor (NNRTI) BHAP U-90152, but not to other NNRTIs. Construction of both recombinant viruses and recombinant RTs containing the V106A, P225H and V106AM P225H mutations revealed that P225H was indeed responsible for the marked potentiation of the antiviral activity of BHAP against the P225H single-mutant virus and the V106AM P225H double-mutant virus when compared to wild-type and V106A single-mutant viruses, respectively. An explanation for the markedly increased sensitivity of the P225H mutant HIV-1 RT to BHAP and not to the other NNRTIs was provided by the unique features of the X-ray structure of the RT-BHAP complex.The reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) is an important target enzyme for the chemotherapy of AIDS because of its key role in virus replication (De Clercq, 1995 a, b). The non-nucleoside RT inhibitors (NNRTIs) represent a wide range of highly specific inhibitors of HIV-1 RT. Although the NNRTIs are potent HIV-1 inhibitors endowed with low toxicity, their clinical use has been questioned owing to the rapid emergence of drugresistant virus variants (De Clercq, 1994 ;Schinazi et al., 1996). Drug resistance to NNRTIs is primarily associated with mutations of amino acids that surround the lipophilic NNRTI-

Effects of the G190A substitution of HIV reverse transcriptase on phenotypic susceptibility of patient isolates to delavirdine

“…Among these, P236L was reported to result in hypersusceptibility to non-BHAP NNRTIs (Dueweke et al, 1993;Fan et al, 1995b;Gerondelis et al, 1999;Olmsted et al, 1996). Conversely, P225H has been reported to arise in vitro following exposure to quinoxaline S-2720, and results in hypersusceptibility to delavirdine, but not to dipiridodiazepinone NNRTIs (Pelemans et al, 1997(Pelemans et al, , 1998. In our cohort, the presence of the G190A substitution was not associated with reduced replication capacity.…”

Computational Analysis of Human Immunodeficiency Virus (HIV) Type-1 Reverse Transcriptase Crystallographic Models Based on Significant Conserved Residues Found in Highly Active Antiretroviral Therapy (HAART)-Treated Patients (Supplementary Material)

“…Pro225 is one of the amino acids forming the entrance rim of the hydrophobic NNRTI-BP, and it is highly conserved in the RTs of HIV-1, HIV-2 and simian immunodeficiency virus (SIV) [73]. This amino acid was well recog-nized by DRY probe (Supplementary Material Fig.…”

Mutational Analysis of Tyr-318 within the Non-nucleoside Reverse Transcriptase Inhibitor Binding Pocket of Human Immunodeficiency Virus Type I Reverse Transcriptase

“…Upon successful homologous recombination, viable recombinant virus could be recovered from the cell culture. The presence of the Tyr-318 mutations was verified by sequencing of the virus DNA samples in an automated laser fluorescent DNA sequencer using the Autoread T7 Sequencing kit from Pharmacia as described previously (10,11).…”