Resistance to N-peptide fusion inhibitors correlates with thermodynamic stability of the gp41 six-helix bundle but not HIV entry kinetics
Autor: | Russell Vassell, Christopher J. De Feo, Wei Wang, Min Zhuang, Meng-Lun Hsieh, Carol D. Weiss |
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Rok vydání: | 2014 |
Předmět: |
HIV entry
Protein Conformation Protein subunit viruses Kinetics Resistance Peptide Biology Gp41 Virus Cell Line Protein structure Viral entry HIV Fusion Inhibitors Virology Drug Resistance Viral Entry kinetics Humans Fusion Helix bundle chemistry.chemical_classification Protein Stability Research Virus Internalization Molecular biology gp41 HIV Envelope Protein gp41 Infectious Diseases chemistry Multiprotein Complexes Biophysics HIV-1 Thermodynamics Mutant Proteins Protein Multimerization Peptide fusion inhibitor |
Zdroj: | Retrovirology |
ISSN: | 1742-4690 |
Popis: | Background The HIV-1 envelope glycoprotein (Env) undergoes conformational changes that mediate fusion between virus and host cell membranes. These changes involve transient exposure of two heptad-repeat domains (HR1 and HR2) in the gp41 subunit and their subsequent self-assembly into a six-helix bundle (6HB) that drives fusion. Env residues and features that influence conformational changes and the rate of virus entry, however, are poorly understood. Peptides corresponding to HR1 and HR2 (N and C peptides, respectively) interrupt formation of the 6HB by binding to the heptad repeats of a fusion-intermediate conformation of Env, making the peptides valuable probes for studying Env conformational changes. Results Using a panel of Envs that are resistant to N-peptide fusion inhibitors, we investigated relationships between virus entry kinetics, 6HB stability, and resistance to peptide fusion inhibitors to elucidate how HR1 and HR2 mutations affect Env conformational changes and virus entry. We found that gp41 resistance mutations increased 6HB stability without increasing entry kinetics. Similarly, we show that increased 6HB thermodynamic stability does not correlate with increased entry kinetics. Thus, N-peptide fusion inhibitors do not necessarily select for Envs with faster entry kinetics, nor does faster entry kinetics predict decreased potency of peptide fusion inhibitors. Conclusions These findings provide new insights into the relationship between 6HB stability and viral entry kinetics and mechanisms of resistance to inhibitors targeting fusion-intermediate conformations of Env. These studies further highlight how residues in HR1 and HR2 can influence virus entry by altering stability of the 6HB and possibly other conformations of Env that affect rate-limiting steps in HIV entry. Electronic supplementary material The online version of this article (doi:10.1186/s12977-014-0086-8) contains supplementary material, which is available to authorized users. |
Databáze: | OpenAIRE |
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