[5-FAM]/[Lys(Dnp)]-SARS-CoV-2 S1/S2 – Fluorescent Peptides

Fluorescence resonance energy transfer (FRET) peptide substrate derived from SARS-CoV-2 spike (S) S1/S2 site. This FRET peptide exhibits internal fluorescence quenching when intact, however hydrolysis of the peptide between the donor/acceptor pair generates fluorescence, enabling the quantitative measure of enzymatic activity. The S1/S2 site of SARS-CoV-2 S is efficiently cleaved by a wide range of proteases including furin. SARS-CoV-2 Spike (S) protein is one of the four essential structural proteins from the coronavirus SARS-CoV-2. S protein is a large, class I viral transmembrane protein essential for viral entry into the cell via binding to the host angiotensin-converting enzyme 2 (ACE2) receptor. S assembles as a trimer on the surface of the virion, giving it its distinctive ‘corona’ or crown-like appearance. The ectodomains of S proteins are divided into two subunits, S1 and S2. S1 helps in host receptor binding and is further divided into two subdomains: N-terminal domain (NTD) and C-terminal domain (CTD), both of which act as receptor-binding domains. The S1 CTD contains the receptor-binding motif (RBM). The S2 subunit accounts for fusion. Peptide contains an N-terminal 5-carboxyfluorescein (5-FAM), a widely used green fluorescent tag and a 2, 4-dinitrophenyl (Dnp) quencher.