Protein Catenation Enhances Both the Stability and Activity of Folded Structural Domains

Catenanes are intriguing molecular architectures with unique properties. Herein, we report the cellular synthesis of protein catenanes containing folded structural domains, aided by synergy between p53 dimerization and SpyTag/SpyCatcher chemistry. Concatenation of green fluorescent protein (GFP) was shown to increase chemical stability without disrupting the fluorescence properties, and concatenated dihydrofolate reductase (DHFR) exhibited a melting temperature around 4 degrees C higher and catalytic activity around 27% higher than the wild-type DHFR and the cyclic/linear controls. Catenation also confers considerable proteolytic resistance on DHFR. The results suggest that catenation could enhance both the stability and activity of folded proteins, thus making topology engineering an attractive approach for tailoring protein properties without varying their native sequences.