Site-specific N-terminal labeling of proteins using sortase-mediated reactions

摘要

For many proteins, the N- or the C-terminus make essential contributions to substrate binding, for protein-protein interactions, or for anchoring the proteins to a membrane. In other circumstances, at least one of the termini is buried within the protein, rendering it inaccessible to labeling. The possibility of selective modification of one of the protein’s termini may present unique opportunities for biochemical and biological applications. We describe sortase-mediated reactions to selectively label the N-terminus of a protein with a variety of functional groups. If sortase, the protein of interest, and a suitably functionalized label are available, the reactions usually require less than 3 hours.