Asparaginyl Ligases: New Enzymes for the Protein Engineer's Toolbox

Enzyme-catalysed site-specific protein modifications enable the precision manufacture of conjugates for the study of protein function and/or for therapeutic or diagnostic applications. Asparaginyl ligases are a class of highly efficient transpeptidases with the capacity to modify proteins bearing only a tripeptide recognition motif. Herein, we review the types of protein modification that are accessible using these enzymes, including N- and C-terminal protein labelling, head-to-tail cyclisation, and protein-protein conjugation. We describe the progress that has been made to engineer highly efficient ligases as well as efforts to chemically manipulate the enzyme reaction to favour product formation. These enzymes are powerful additions to the protein engineer's toolbox.

Automated summary

Asparaginyl ligases are efficient transpeptidases capable of modifying proteins with a tripeptide recognition motif. Various protein modifications, such as N- and C-terminal labeling, head-to-tail cyclization, and protein-protein conjugation, can be achieved using these enzymes. Efforts to engineer highly efficient ligases and manipulate enzyme reactions chemically have expanded the capabilities of protein engineers.