Effect of catenation on protein folding stability.

Building on previous studies of the effects of covalent linking and backbone cyclization on protein folding stability, a theory is developed for the stabilization effect of catenating a dimeric protein. Relative to covalent linking, catenation is up to 1000-fold more powerful in stabilizing the folded structure. This dramatic stabilization derives from the dual effects of backbone cyclization and constrained relative motion between the subunits afforded by the catenane topology.