Tocris Bioscience™ Ac-Cys-NHMe

Ac-Cys-NHMe is a non-canonical amino acid that is an essential building block for lysine acylation using conjugating enzymes (LACE) technique. LACE is a chemoenzymatic approach that uses an E2 small ubiquitin-like modifier (SUMO)-conjugating enzyme, Ubc9, to conjugate peptide thioesters containing a C-terminal ubiquitin-derived sequence (LRLRGG) to a lysine residue located in a recognition sequence (IKQE) on a protein via an isopeptide bond. Ac-Cys-NHMe can be reacted with a peptide hydrazide to form a reactive peptide thioester, which is the substrate for Ubc9. LACE enables the site-specific modification of proteins at lysine residues to allow attachment of biochemical probes such as fluorophores to proteins or to engineer proteins for site-specific delivery.