2009/02/07 by Peng Wu, Wenqing Shui, Brian L. Carlson +4 · 1 citation
Medicine · Biochemistry, Genetics and Molecular Biology · #Monoclonal and Polyclonal Antibodies Research #Peptidase Inhibition and Analysis #Protein purification and stability
paper · doi:10.1073/pnas.0807820106
openalex publication_date 2009/02/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The properties of therapeutic proteins can be enhanced by chemical modification. Methods for site-specific protein conjugation are critical to such efforts. Here, we demonstrate that recombinant proteins expressed in mammalian cells can be site-specifically modified by using a genetically encoded aldehyde tag. We introduced the peptide sequence recognized by the endoplasmic reticulum (ER)-resident formylglycine generating enzyme (FGE), which can be as short as 6 residues, into heterologous proteins expressed in mammalian cells. Cotranslational modification of the proteins by FGE produced products bearing a unique aldehyde group. Proteins bearing this "aldehyde tag" were chemically modified by selective reaction with hydrazide- or aminooxy-functionalized reagents. We applied the technique to site-specific modification of monoclonal antibodies, the fastest growing class of biopharmaceuticals, as well as membrane-associated and cytosolic proteins expressed in mammalian cells.