Conformational Changes in HIV-1 gp41 in the Course of HIV-1 Envelope Glycoprotein-Mediated Fusion and Inactivation
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- 作者：Antony S. Dimitrov ; John M. Louis ; Carole A. Bewley ; G. Marius Clore ; and Robert Blumenthal
- 刊名：Biochemistry
- 出版年：2005
- 出版时间：September 20, 2005
- 年：2005
- 卷：44
- 期：37
- 页码：12471 - 12479
- 全文大小：230K
- 年卷期：v.44,no.37(September 20, 2005)
- ISSN：1520-4995
文摘
HIV-1 envelope glycoprotein-mediated fusion is driven by the concerted coalescence of theHIV-1 gp41 N- and C-helical regions, which results in the formation of 6-helix bundles. These two regionsare considered prime targets for peptides and antibodies that inhibit HIV-1 entry. However, the parametersthat govern this inhibition have yet to be elucidated. We address this issue by monitoring the temporalsequence of conformational states of HIV-1 gp41 during the course of HIV-1-mediated cell-cell fusionby quantitative video microscopy using reagents that bind to N- and C-helical regions, respectively. Env-expressing cells were primed by incubation with target cells at different times at 37 
C followed bywashing. The reactivity of triggered gp41 to the NC-1 monoclonal antibody, which we demonstrate hereto bind to N-helical gp41 trimers, increased rapidly to a maximal level in the primed state but decreasedonce stable fusion junctions had formed. In contrast, reactivity with 5-helix, which binds to the C-helicalregion of gp41, increased continuously as a function of time following the priming. The peptide N36Mut(e,g)reduced NC-1 monoclonal antibody binding and enhanced 5-helix binding, consistent with the notionthat this molecule promotes dissociation of gp41 trimers. This inactivation pathway may be important forthe design of entry inhibitors and vaccine candidates.
C followed bywashing. The reactivity of triggered gp41 to the NC-1 monoclonal antibody, which we demonstrate hereto bind to N-helical gp41 trimers, increased rapidly to a maximal level in the primed state but decreasedonce stable fusion junctions had formed. In contrast, reactivity with 5-helix, which binds to the C-helicalregion of gp41, increased continuously as a function of time following the priming. The peptide N36Mut(e,g)reduced NC-1 monoclonal antibody binding and enhanced 5-helix binding, consistent with the notionthat this molecule promotes dissociation of gp41 trimers. This inactivation pathway may be important forthe design of entry inhibitors and vaccine candidates.