A Noncanonical Function of Sortase Enables Site‐Specific Conjugation of Small Molecules to Lysine Residues in Proteins |
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| Authors: | Joseph J Bellucci Dr Jayanta Bhattacharyya Prof Ashutosh Chilkoti |
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| Affiliation: | Department of Biomedical Engineering, Duke University, Durham, NC 27708 (USA) http://www.chilkotilab.pratt.duke.edu |
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| Abstract: | We provide the first demonstration that isopeptide ligation, a noncanonical activity of the enzyme sortase A, can be used to modify recombinant proteins. This reaction was used in vitro to conjugate small molecules to a peptide, an engineered targeting protein, and a full‐length monoclonal antibody with an exquisite level of control over the site of conjugation. Attachment to the protein substrate occurred exclusively through isopeptide bonds at a lysine ε‐amino group within a specific amino acid sequence. This reaction allows more than one molecule to be site‐specifically conjugated to a protein at internal sites, thereby overcoming significant limitations of the canonical native peptide ligation reaction catalyzed by sortase A. Our method provides a unique chemical ligation procedure that is orthogonal to existing methods, supplying a new method to site‐specifically modify lysine residues that will be a valuable addition to the protein conjugation toolbox. |
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| Keywords: | biotechnology protein modification bioconjugation sortase |
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