Research + Discoveries

Three-in-One Chromatography-Free Purification, Tag Removal, and Site-Specific Modification of Recombinant Fusion Proteins Using Sortase A and Elastin-like Polypeptides

Recently reported in Angewandte Chemie, the Chilkoti and McCafferty groups at Duke have collaborated to discover a "three-in-one" facile method for the chromatography-free purification of recombinant proteins and optional, site-specific conjugation of the protein to a small moleule. The investigators have prepared a first-in-class recombinant expression and purification system that combines elastin-like polypeptide sequences (ELPs), which transition between soluble and insoluble phases with changes in temperature, with staphylococcal sortas SrtA transpeptidase mediated fusion protein removal.  Because sortase transpeptidase cleaves via a stable thioester enzyme-acyl intermediate, interception by nucleophilic small molecules can produce terminally-labeled proteins, as well a providing reactive groups for additional ligation chemistry to recombinant protein and peptide fragments.