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Amino acid substitutions in HIV-1 reverse transcriptase with corresponding residues from HIV-2. Effect on kinetic constants and inhibition by non-nucleoside analogs

Authors :
Daniel J. Greenwood
Cheng-Kon Shih
Thomas C. Warren
G Piras
D Richman
Christine A. Grygon
R C Cousins
Janice M. Rose
Albino Bacolla
Richard H. Ingraham
Source :
Journal of Biological Chemistry. 268:16571-16577
Publication Year :
1993
Publisher :
Elsevier BV, 1993.

Abstract

Nevirapine is a highly potent and specific inhibitor of human immunodeficiency virus type 1 (HIV-1) polymerase, but is inactive against HIV-2 and other polymerase. Previous studies demonstrated that residues 176-190 of HIV-1 reverse transcriptase (RT) can confer nevirapine sensitivity to HIV-2 RT. To better characterize the role of this sequence in HIV-1 RT, we have progressively substituted residues 176-190 of HIV-2 RT for those of HIV-1 RT and monitored the impact on the kinetic properties; inhibitory activity of nevirapine (11-cyclopropyl-5,11-dihydro-4-methyl-6H-dipyrido[2,3-b:2',3'-e] [1,4]diazepin-6-one), E-BPU (5-ethyl-1-benzyloxymethyl-6-(phenylthio)-uracil), and TIBO-R82150 ((+)-S-4,5,6,7-tetrahydro-5-methyl-6-(3-methyl-2-butenyl)imidazo[4,5,1-j k] [1,4]benzodiazepin-2(1H)-thione); and inhibitor-induced fluorescence changes of the mutant enzymes. The study revealed that in addition to Try-181 and Tyr-188, a new amino acid residue (Gly-190) plays an important role in determining susceptibility to nevirapine and E-BPU, but not to TIBO-R82150. These data argue that these non-nucleoside inhibitors fit differently, even though they share a common binding pocket. Nevirapine was seen to exert inhibitory activity by altering the interaction of the enzyme with the template-primer. Kinetic parameters were modulated by the template (DNA versus RNA) as well as by some of the mutations.

Details

ISSN :
00219258
Volume :
268
Database :
OpenAIRE
Journal :
Journal of Biological Chemistry
Accession number :
edsair.doi...........0ddc6e5b582ff6ecf0cfa7b0f303a9c9