SpyTag peptide (SpyTag)

SpyTag is a 13-amino acid peptide (AHIVMVDAYKPTK) derived from the CnaB2 domain of the fibronectin-binding protein FbaB from Streptococcus pyogenes (Zakeri et al., 2012, PNAS). It is engineered to react spontaneously and irreversibly with its partner protein, SpyCatcher, through the formation of a covalent isopeptide bond between an aspartic acid side chain on the tag and a lysine side chain on the catcher (Li et al., 2014, Structure). While not a therapeutic target in the classical sense, SpyTag serves as a robust platform for protein engineering and vaccine development, enabling the modular assembly of complex structures like virus-like particles (VLPs) (Bruun et al., 2018, ACS Nano). In clinical applications, the technology is used to link antigens to scaffolds to enhance immune responses, as demonstrated in several COVID-19 vaccine candidates (Rahikainen et al., 2021, Angewandte Chemie). The system's high stability across various temperatures and pH levels makes it a versatile tool for creating complex bioconjugates and synthetic organelles in both research and therapeutic contexts (Sutherland et al., 2018, Chemical Science).

Other names

FbaB-derived peptideCnaB2-derived peptide tagSpyTag/SpyCatcher system component

Spontaneous autocatalytic formation of an intermolecular isopeptide bond between the Asp117 residue of SpyTag and the Lys31 residue of SpyCatcher (Zakeri et al., 2012).