title: Direct evidence of the multidimensionality of the free-energy landscapes of proteins revealed by mechanical probes.
abstract: The study of mechanical unfolding, through the combined efforts of atomic force microscopy and simulation, is yielding fresh insights into the free-energy landscapes of proteins. Thus far, experiments have been mostly analyzed with one-dimensional models of the free-energy landscape. We show that as the two ends of a protein, filamin, are pulled apart at a speed tending to zero, the measured mechanical strength plateaus at approximately 30 pN instead of going toward zero, deviating from the Bell model. The deviation can only be explained by a switch between parallel pathways. Insightful analysis of mechanical unfolding kinetics needs to account for the multidimensionality of the free-energy landscapes of proteins, which are crucial for understanding the behavior of proteins under the small forces experienced in vivo.
authors.affiliation: Institute of Molecular and Cell Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Zu Thur
authors.initials: ZT
authors.lastname: Yew
authors.forename: Michael
authors.initials: M
authors.lastname: Schlierf
authors.forename: Matthias
authors.initials: M
authors.lastname: Rief
authors.forename: Emanuele
authors.initials: E
authors.lastname: Paci
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D008846:Micromanipulation / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D011506:Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D013314:Stress, Mechanical
chemical_list: D011506:Proteins