Engineering an artificial catch bond using mechanical anisotropy

• Published in: Nature communications Vol. 15; no. 1; p. 3019
• Main Authors: Liu, Zhaowei, Liu, Haipei, Vera, Andrés M., Yang, Byeongseon, Tinnefeld, Philip, Nash, Michael A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-04-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 147/136; 147/3; 631/114/2397; 631/45/56; 631/57/2265; 631/80/79; 82/16; 82/80; 82/83; Adhesion; Adhesives; Anisotropy; Bacteria; Chemical synthesis; Cohesin; Cohesins; Engineers; Humanities and Social Sciences; Humans; Kinetics; Mechanical Phenomena; multidisciplinary; N-Terminus; Protein Binding; Protein interaction; Proteins; Science; Science (multidisciplinary); Spectroscopy
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-46858-9

Catch bonds are a rare class of protein-protein interactions where the bond lifetime increases under an external pulling force. Here, we report how modification of anchor geometry generates catch bonding behavior for the mechanostable Dockerin G:Cohesin E (DocG:CohE) adhesion complex found on human gut bacteria. Using AFM single-molecule force spectroscopy in combination with bioorthogonal click chemistry, we mechanically dissociate the complex using five precisely controlled anchor geometries. When tension is applied between residue #13 on CohE and the N-terminus of DocG, the complex behaves as a two-state catch bond, while in all other tested pulling geometries, including the native configuration, it behaves as a slip bond. We use a kinetic Monte Carlo model with experimentally derived parameters to simulate rupture force and lifetime distributions, achieving strong agreement with experiments. Single-molecule FRET measurements further demonstrate that the complex does not exhibit dual binding mode behavior at equilibrium but unbinds along multiple pathways under force. Together, these results show how mechanical anisotropy and anchor point selection can be used to engineer artificial catch bonds.
Catch bonds are unique protein-protein interactions where the bond lifetime increases under external pulling forces. Here, the authors engineer an artificial catch bond based on a non-catch bonding human gut bacterial adhesion protein complex.