Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics

Viruses

Kartik Chandran¹  J.Maximilian Fels¹  NatashaD. Durham²  JamesB. Munro²  Ramesh Govindan²  AngelaR. Howard³  Fernando Senjobe³  Jeremy Luban⁴  WilliamE. Diehl⁴ 

[1] Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA;Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, USA;Department of Molecular Biology and Microbiology, Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, USA;Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA;

关键词: ebola virus;    envelope glycoprotein;    conformational dynamics;    single-molecule fret;    virus entry;   

DOI  :  10.3390/v12010103

来源: DOAJ

【 摘 要 】

The Ebola virus (EBOV) envelope glycoprotein (GP) mediates the fusion of the virion membrane with the membrane of susceptible target cells during infection. While proteolytic cleavage of GP by endosomal cathepsins and binding of the cellular receptor Niemann-Pick C1 protein (NPC1) are essential steps for virus entry, the detailed mechanisms by which these events promote membrane fusion remain unknown. Here, we applied single-molecule Förster resonance energy transfer (smFRET) imaging to investigate the structural dynamics of the EBOV GP trimeric ectodomain, and the functional transmembrane protein on the surface of pseudovirions. We show that in both contexts, pre-fusion GP is dynamic and samples multiple conformations. Removal of the glycan cap and NPC1 binding shift the conformational equilibrium, suggesting stabilization of conformations relevant to viral fusion. Furthermore, several neutralizing antibodies enrich alternative conformational states. This suggests that these antibodies neutralize EBOV by restricting access to GP conformations relevant to fusion. This work demonstrates previously unobserved dynamics of pre-fusion EBOV GP and presents a platform with heightened sensitivity to conformational changes for the study of GP function and antibody-mediated neutralization.

【 授权许可】

Unknown