Viral Fusion
Viral Fusion - Related Videos
14:59
Method for Measurement of Viral Fusion Kinetics at the Single Particle Level
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Cited by 11 •
2009
We present an in vitro, two-color fluorescence assay to visualize the fusion of single virus particles with a fluid target bilayer. By labeling viral particles with fluorophores that differentially stain the viral membrane and its interior, we are able to monitor the kinetics of hemifusion and pore formation.
02:38
An Assay to Evaluate the Effect of Test Compounds on Viral Entry and Fusion in Host Cells
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2025
This video demonstrates an assay to evaluate antiviral agents that target specific steps of the viral entry into host cells and fusion with the endosome. The cells are incubated at a low temperature and then infected with HCV. The low temperature permits viral binding to host cells but inhibits internalization via endocytosis. The test antiviral compound is added, and the cells are incubated at physiological temperature. This shift to a higher temperature facilitates viral entry and allows...
02:45
Assessment of Viral Fusion Inhibitors Using a Cre-Inducible Fluorescent Reporter
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2026
Source: Esposito, A. M.,et al. High-throughput Cre-Lox Activated Viral Membrane Fusion Assay to Identify Inhibitors of HIV-1 Viral Membrane Fusion. J. Vis. Exp. (2018)This video demonstrates a co-culture fluorescent assay to monitor cell-to-cell viral transmission. The assay uses a red-to-green reporter cassette to visualize viral membrane fusion and evaluate the efficacy of test compounds in blocking viral entry.
07:22
A High-throughput Cre-Lox Activated Viral Membrane Fusion Assay to Identify Inhibitors of HIV-1 Viral Membrane Fusion
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Cited by 8 •
2018
We describe a cell-based assay to report on HIV-1 fusion via the expression of green fluorescent protein detectable by flow cytometry or fluorescence microscopy. It can be used to test inhibitors of viral entry (specifically at the fusion step) in cell-free and cell-to-cell infection systems.
02:45
Nuclear Fusion
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2020
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion. The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and ultimately produce one helium nucleus and two positrons. A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about...
FAQs
A fusion protein first participates in receptor or attachment-factor engagement, then undergoes a structural rearrangement. This change exposes a hydrophobic fusion peptide, which inserts into the host-cell membrane and helps bring the viral and cellular membranes together. Tracking these transitions explains how an initial binding event is converted into membrane merger and eventual delivery of the viral genome or core.
For some viruses, acidity inside an endosome provides the activating condition that triggers the fusion protein’s structural change. Without that signal, the fusion peptide may remain unexposed and membrane merger may not proceed. This dependence links viral entry to the route taken through the cell and identifies the activation step as a potential point for experimental or therapeutic intervention.
Receptor or attachment-factor binding helps the virus engage the appropriate host-cell surface and can initiate changes in the fusion protein. Membrane merger is a later event in which the activated protein exposes its hydrophobic fusion peptide and draws the two membranes together. Separating these stages helps researchers determine whether an entry-blocking strategy prevents attachment, activation, or fusion itself.
A useful sequence begins with identifying the receptor or attachment factor involved, followed by determining whether an acidic endosomal condition activates the fusion protein. Researchers then examine the protein’s structural rearrangement, fusion-peptide exposure, membrane approximation, and delivery of the viral genome or core. This progression connects molecular changes with the infection-initiating entry outcome.
The fusion process presents several possible intervention points, including receptor or attachment-factor engagement, the structural rearrangement of the fusion protein, and exposure or action of the hydrophobic fusion peptide. Compounds designed to interfere with these steps could prevent membrane merger before the viral genome or core enters the cell, making fusion mechanisms useful for identifying antiviral targets.
Fusion research shows how pathogens cross cellular barriers and initiates infection, while also highlighting stages that host defenses may recognize or block. These insights connect viral entry with immune protection and help explain how interventions could stop infection before intracellular replication begins. The same mechanistic knowledge supports vaccine development by identifying viral fusion components relevant to protective targeting.