Chimeric human immunodeficiency virus type 1/type 2 reverse transcriptases display reversed sensitivity to nonnucleoside analog inhibitors.

Abstract

Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), an important therapeutic target in the treatment of AIDS, is effectively inhibited by a class of nonnucleoside analog compounds that includes nevirapine (BI-RG-587) and tetrahydroimidazo[4,5,1-jk]-[1,4]benzodiazepin-2(1H)-one and -thione. We show that both tyrosine residues at positions 181 and 188 flanking the putative catalytic site of HIV-1 RT are required for sensitivity of the enzyme to these compounds. HIV-2 RT, which does not have tyrosines at these positions, is resistant to these nonnucleoside analog inhibitors. Substitution of the HIV-2 RT amino acid residues at position 181 or 188 into HIV-1 RT results in an enzyme that is resistant to these compounds while retaining sensitivity to 3'-azido-2',3'-dideoxythymidine triphosphate. HIV-2 RT substituted with amino acids 176-190 from HIV-1 RT acquires sensitivity to these nonnucleoside analog inhibitors.

Simultaneous mutations at Tyr‐181 and Tyr‐188 in HIV‐1 reverse transcriptase prevents inhibition of RNA‐dependent DNA polymerase activity by the bisheteroarylpiperazine (BHAP) U‐90152s

“…consistent with the previous chemical cross-linking studies implicating the involvement of these residues in drug binding [17][18][19]. The replacement of Tyr-181 or Tyr-188 with the corresponding HIV-2 RT amino acids (Ile-181 or Leu-188) resulted in HIV-1 RT mutants which were insensitive to L-697,661, nevirapine, and TIBO 82913 [20].…”

“…Therefore, two double mutants were cloned, expressed, and purified. The double mutant Y 181 I/Y 188L carried amino acid substitutions from HIV-2 RT and had been reported by others [18,19,27]. The other double mutant Y181C/Y188L has not been reported and contains amino acid substitutions based on the presence of ~ndividual mutations Y181C [12] or Y188L [14] in resistant viral solates from patients treated with NNRTIs.…”

“…It has been reported that an HIV-2 RT mutant with amino acid substitutions 176-190 from HIV-1 RT, called RT-2 (176-190), acquires sensitivity to nevirapine and TIBO R82913 [18,19]. We also constructed an HIV-2 RT substituted with the corresponding amino acids 176-190 (PDIVIYQYMDDLYV-G) from HIV-1 RT and showed that its U-90152S-sensitivity was indistinguishable from the wild type HIV-1 RT (Table 2).…”

“…have been noted from an alignment of sequences in the fl strands 5, 6, 9, 10, 12, 13, and 14 [17][18][19][20][21]28]. These ]~ strands are important because they form the inhibitor binding pocket and are close to the polymerase active site [16,[34][35][36].…”

HIV-1 Reverse Transcriptase: a potential target for marine products

“…Apparently these marine products act as NNRTI. The NNRTI were fi rst described when TIBO and nevirapine derivatives were discovered during research on HIV-1 RT inhibition (Pauwels et al, 1990, Shih et al, 1991. NNRTI are chemically diverse, with one class being considerably different from another in terms of chemical composition and size.…”