Influence of Fluorination on Single-Molecule Unfolding and Rupture Pathways of a Mechanostable Protein Adhesion Complex.

ABSTRACT: We investigated the influence of fluorination on unfolding and unbinding reaction pathways of a mechanostable protein complex comprising the tandem dyad XModule-Dockerin bound to Cohesin. Using single-molecule atomic force spectroscopy, we mapped the energy landscapes governing the unfolding and unbinding reactions. We then used sense codon suppression to substitute trifluoroleucine in place of canonical leucine globally in XMod-Doc. Although TFL substitution thermally destabilized XMod-Doc, it had little effect on XMod-Doc:Coh binding affinity at equilibrium. When we mechanically dissociated global TFL-substituted XMod-Doc from Coh, we observed the emergence of a new unbinding pathway with a lower energy barrier. Counterintuitively, when fluorination was restricted to Doc, we observed mec

SUBMITTER: Yang B 

PROVIDER: S-EPMC7729889 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature