This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Maga, G.
Right arrow Articles by Spadari, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Maga, G.
Right arrow Articles by Spadari, S.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, May 2000, p. 1186-1194, Vol. 44, No. 5
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Selective Interaction of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Nonnucleoside Inhibitor Efavirenz and Its Thio-Substituted Analog with Different Enzyme-Substrate Complexes

Giovanni Maga,1 Daniela Ubiali,2 Raul Salvetti,2 Massimo Pregnolato,2,* and Silvio Spadari1

Istituto di Genetica Biochimica ed Evoluzionistica IGBE-C.N.R.1 and Dipartimento di Chimica Farmaceutica, Università degli Studi,2 I-27100 Pavia, Italy

Received 16 August 1999/Returned for modification 24 November 1999/Accepted 27 December 1999

Accumulating data have brought the nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) into the forefront of antiretroviral therapy. Among the emerging compounds in this class, a particularly attractive one is efavirenz (Sustiva), recently approved for clinical use by the U.S. Food and Drug Administration. In the present study, the equilibrium dissociation constants for efavirenz binding to the different catalytic forms of human immunodeficiency virus type 1 RT as well as the association and dissociation rates have been determined using a steady-state kinetic approach. In addition, the same enzymological analysis has been extended to the thio-substituted analog, sefavirenz, which showed comparable activity in vitro against RT. Both compounds have been found to act as purely uncompetitive inhibitors at low drug concentrations (5 to 50 nM) and as mixed noncompetitive inhibitors at higher doses (50 to 500 nM). This behavior can be interpreted in terms of the relative affinities for the different catalytic forms of the enzyme. Both efavirenz and sefavirenz showed increasing affinities for the different forms of RT in the following order: free enzyme < (i.e., bound with lower affinity) binary RT-template-primer (TP) complex < ternary RT-TP-deoxynucleoside triphosphate (dNTP) complex. The rate of binding of the two inhibitors to the different enzyme-substrate complexes was well below the diffusion limit (on the order of 104 M-1 s-1); however, both inhibitors, when bound to the ternary RT-TP-dNTP complex, showed very low dissociation rates, on the order of 10-4 s-1 for both compounds, typical of tightly binding inhibitors. Thus, efavirenz and its thio-substituted derivative sefavirenz appear to be peculiar in their mechanism of action, being selective tightly binding inhibitors of the ternary RT-TP-dNTP complex. Efavirenz is the first clinically approved NNRTI to show this property.

* Corresponding author. Mailing address: Dipartimento di Chimica Farmaceutica, via Taramelli 12, I-27100 Pavia, Italy. Phone: 39-0382-507583. Fax: 39-0382-422975. E-mail: maxp{at}pbl.unipv.it.

Antimicrobial Agents and Chemotherapy, May 2000, p. 1186-1194, Vol. 44, No. 5
0066-4804/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Radzio, J., Sluis-Cremer, N. (2008). Efavirenz Accelerates HIV-1 Reverse Transcriptase Ribonuclease H Cleavage, Leading to Diminished Zidovudine Excision. Mol. Pharmacol. 73: 601-606 [Abstract] [Full Text]  
  • Basavapathruni, A., Anderson, K. S. (2007). Reverse transcription of the HIV-1 pandemic. FASEB J. 21: 3795-3808 [Abstract] [Full Text]  
  • Aguiar, R. S., Costa, L. J., Pereira, H. S., Brindeiro, R. M., Tanuri, A. (2007). Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification. Antimicrob. Agents Chemother. 51: 638-644 [Abstract] [Full Text]  
  • Zhang, Z., Walker, M., Xu, W., Shim, J. H., Girardet, J.-L., Hamatake, R. K., Hong, Z. (2006). Novel nonnucleoside inhibitors that select nucleoside inhibitor resistance mutations in human immunodeficiency virus type 1 reverse transcriptase.. Antimicrob. Agents Chemother. 50: 2772-2781 [Abstract] [Full Text]  
  • Cancio, R., Silvestri, R., Ragno, R., Artico, M., De Martino, G., La Regina, G., Crespan, E., Zanoli, S., Hubscher, U., Spadari, S., Maga, G. (2005). High Potency of Indolyl Aryl Sulfone Nonnucleoside Inhibitors towards Drug-Resistant Human Immunodeficiency Virus Type 1 Reverse Transcriptase Mutants Is Due to Selective Targeting of Different Mechanistic Forms of the Enzyme. Antimicrob. Agents Chemother. 49: 4546-4554 [Abstract] [Full Text]  
  • Locatelli, G. A., Campiani, G., Cancio, R., Morelli, E., Ramunno, A., Gemma, S., Hubscher, U., Spadari, S., Maga, G. (2004). Effects of Drug Resistance Mutations L100I and V106A on the Binding of Pyrrolobenzoxazepinone Nonnucleoside Inhibitors to the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Catalytic Complex. Antimicrob. Agents Chemother. 48: 1570-1580 [Abstract] [Full Text]  
  • Peletskaya, E. N., Kogon, A. A., Tuske, S., Arnold, E., Hughes, S. H. (2004). Nonnucleoside Inhibitor Binding Affects the Interactions of the Fingers Subdomain of Human Immunodeficiency Virus Type 1 Reverse Transcriptase with DNA. J. Virol. 78: 3387-3397 [Abstract] [Full Text]  
  • Motakis, D., Parniak, M. A. (2002). A Tight-Binding Mode of Inhibition Is Essential for Anti-Human Immunodeficiency Virus Type 1 Virucidal Activity of Nonnucleoside Reverse Transcriptase Inhibitors. Antimicrob. Agents Chemother. 46: 1851-1856 [Abstract] [Full Text]  
  • Tachedjian, G., Orlova, M., Sarafianos, S. G., Arnold, E., Goff, S. P. (2001). From the Cover: Nonnucleoside reverse transcriptase inhibitors are chemical enhancers of dimerization of the HIV type 1 reverse transcriptase. Proc. Natl. Acad. Sci. USA 98: 7188-7193 [Abstract] [Full Text]  
  • Maga, G., Hübscher, U., Pregnolato, M., Ubiali, D., Gosselin, G., Spadari, S. (2001). Potentiation of Inhibition of Wild-Type and Mutant Human Immunodeficiency Virus Type 1 Reverse Transcriptases by Combinations of Nonnucleoside Inhibitors and D- and L-({beta})-Dideoxynucleoside Triphosphate Analogs. Antimicrob. Agents Chemother. 45: 1192-1200 [Abstract] [Full Text]  
  • Maga, G., Ramunno, A., Nacci, V., Locatelli, G. A., Spadari, S., Fiorini, I., Baldanti, F., Paolucci, S., Zavattoni, M., Bergamini, A., Galletti, B., Muck, S., Hubscher, U., Giorgi, G., Guiso, G., Caccia, S., Campiani, G. (2001). The Stereoselective Targeting of a Specific Enzyme-Substrate Complex Is the Molecular Mechanism for the Synergic Inhibition of HIV-1 Reverse Transcriptase by (R)-(-)-PPO464. A NOVEL GENERATION OF NONNUCLEOSIDE INHIBITORS. J. Biol. Chem. 276: 44653-44662 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»