ABSTRACT
FRET is ascribed to the spectral overlapping of upconversion luminescence and the absorption of AuNPs. This experiment enables early-stage coronavirus detection. The results show a sensitivity of 100 fM for the detection of COVID-19 DNA. © 2022 The Author(s)
ABSTRACT
FRET is ascribed to the spectral overlapping of upconversion luminescence and the absorption of AuNPs. This experiment enables early-stage coronavirus detection. The results show a sensitivity of 100 fM for the detection of COVID-19 DNA. © 2022 The Author(s)
ABSTRACT
As a major surface glycoprotein of enveloped viruses, the virus spike protein is a primary target for vaccines and anti-viral treatments. Current vaccines aiming at controlling the COVID-19 pandemic are mostly directed against the SARS-CoV-2 spike protein. To promote virus entry and facilitate immune evasion, spikes must be dynamic. Interactions with host receptors and coreceptors trigger a cascade of conformational changes/structural rearrangements in spikes, which bring virus and host membranes in proximity for membrane fusion required for virus entry. Spike-mediated viral membrane fusion is a dynamic, multi-step process, and understanding the structure-function-dynamics paradigm of virus spikes is essential to elucidate viral membrane fusion, with the ultimate goal of interventions. However, our understanding of this process primarily relies on individual structural snapshots of endpoints. How these endpoints are connected in a time-resolved manner, and the order and frequency of conformational events underlying virus entry, remain largely elusive. Single-molecule Förster resonance energy transfer (smFRET) has provided a powerful platform to connect structure-function in motion, revealing dynamic aspects of spikes for several viruses: SARS-CoV-2, HIV-1, influenza, and Ebola. This review focuses on how smFRET imaging has advanced our understanding of virus spikes' dynamic nature, receptor-binding events, and mechanism of antibody neutralization, thereby informing therapeutic interventions.
Subject(s)
Fluorescence Resonance Energy Transfer/methods , Host Microbial Interactions/immunology , Membrane Fusion , Receptors, Virus/immunology , Spike Glycoprotein, Coronavirus/immunology , Virus Internalization , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Humans , Protein BindingABSTRACT
Adenosine 5'-triphosphate (ATP), the major energy currency of the cell, is involved in many cellular processes, including the viral life cycle, and can be used as an indicator of early signs of cytopathic effect (CPE). In this study, we demonstrated that CPE can be analyzed using an FRET-based ATP probe named ATP indicator based on Epsilon subunit for Analytical Measurements (ATeam). The results revealed that as early as 3 hr, the virus infected cells showed a significantly different Venus/cyan fluorescent protein (CFP) ratio compared to the mock-infected cells. The ATeam technology is therefore useful to determine the early signs of ATP-based CPE as early as 3 hr without morphology-based CPE by light microscopy, and enables high throughput determination of the presence of microorganisms in neglected samples stored in laboratories.