Site-specific protein modification on living cells catalyzed by Sortase

Chembiochem. 2008 Mar 25;9(5):802-7. doi: 10.1002/cbic.200700614.


The use of enzymes is a promising approach for site-specific protein modification on living cells owing to their substrate specificity. Herein we describe a general strategy for the site-specific modification of cell surface proteins with synthetic molecules by using Sortase, a transpeptidase from Staphylococcus aureus. The short peptide tag LPETGG is genetically introduced to the C terminus of the target protein, expressed on the cell surface. Subsequent addition of Sortase and an N-terminal triglycine-containing probe results in the site-specific labeling of the tagged protein. We were successful in the C-terminal-specific labeling of osteoclast differentiation factor (ODF) with a biotin- or fluorophore-containing short peptide on the living cell surface. The labeling reaction occurred efficiently in serum-containing medium, as well as serum-free medium or PBS. The labeled products were detected after incubation for 5 min. In addition, site-specific protein-protein conjugation was successfully demonstrated on a living cell surface by the Sortase-catalyzed reaction. This strategy provides a powerful tool for cell biology and cell surface engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoacyltransferases / chemistry*
  • Bacterial Proteins / chemistry*
  • Biotin / chemistry
  • Catalysis
  • Cell Survival
  • Cells, Cultured
  • Cysteine Endopeptidases / chemistry*
  • Fluorescent Dyes / chemistry
  • Humans
  • Membrane Proteins / chemistry*
  • Molecular Structure
  • Peptides / chemistry
  • Protein Binding
  • RANK Ligand / chemistry
  • Staphylococcus aureus / enzymology
  • Substrate Specificity
  • Surface Properties
  • Time Factors


  • Bacterial Proteins
  • Fluorescent Dyes
  • Membrane Proteins
  • Peptides
  • RANK Ligand
  • Biotin
  • Aminoacyltransferases
  • sortase A
  • Cysteine Endopeptidases