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A Fluorogenic Peptide Cleavage Assay to Screen for Proteolytic Activity: Applications for coronavirus spike protein activation
Published on: January 9, 2019
Protease-Mediated Shedding and Intermittent Mobility of the SARS-CoV-2 Delta Variant
Manorama Dey1, Poojitha Sai Potharaju2, Khushika3
1Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India.
Abstract:
We report that soluble serine proteases such as trypsin and chymotrypsin trigger the shedding and/or detachment of SARS-CoV-2 particles bound to lipid membranes. Shedding kinetics were evaluated upon fluorescence imaging of the labeled virus particles on native membrane mimics. The temporal change in the fluorescence signal, supported by kinetic data from SPR, confirms the fastest shedding of the Delta variant. B.1.1.8 (near Wuhan) and Omicron exhibit comparable shedding kinetics. Membrane-bound Delta variants become laterally mobile upon protease treatment. The other variants are shed from the immobile state. The mean square displacement and probability distribution of lateral displacements of the particles evaluated upon single-particle tracking reveal Brownian yet non-Gaussian diffusion, arising from the intermittent mobility of the Delta variant. These findings are discussed with a model that describes the "hopping motion" of the Delta variant caused by dynamic membrane binding in the presence of a soluble serine protease.
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