This peptide sequence represents a second furin-like cleavage site of the Spike (S) protein also thought to participate in the process of viral entry into host cell. The sequence at the S2 site (KR↓SF) contains two basic residues (P1 and P2) and a hydrophobic P3 residue. This site is identical between the SARS-CoV-2 and SARS-CoV. This peptide has been labeled with QXL®520 and 5-FAM.
Coutard B, et al. The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade. Antiviral Res. 2020 Apr;176:104742. doi: 10.1016/j.antiviral.2020.104742.
Sequence (One-Letter Code)
Sequence (Three-Letter Code)
QXL®520 - Ser - Lys - Pro - Ser - Lys - Arg - Ser - Phe - Ile - Glu - Asp - Lys(5 - FAM) - OH