title: Cracking phase diagram for the dynamics of an enzyme.
abstract: We measure the ensemble averaged deformation of an enzyme for an oscillating applied force. From the low frequency divergence of the mechanical susceptibility for the hinge motion of guanylate kinase we obtain a nonequilibrium phase diagram in the frequency-force plane. A phase line separates linear elasticity dynamics from softer (viscoelastic) dynamics. The hinge motion corresponds to crossing this phase line (not to a soft linear elastic mode). The phase line is dramatically shifted in the closed state compared to the open state of the enzyme.
authors.affiliation: Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095-1547, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Qu
authors.forename: Jonathan
authors.initials: J
authors.lastname: Landy
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zocchi
mesh_terms: D001703:Biophysics / Q000379:methods*; D004247:DNA / Q000737:chemistry; D004548:Elasticity; D004798:Enzymes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D051528:Guanylate Kinases / Q000737:chemistry*; D007477:Ions; D008027:Light; D016014:Linear Models; D053768:Metal Nanoparticles / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009038:Motion; D016296:Mutagenesis; D009169:Mycobacterium tuberculosis / Q000201:enzymology; D009991:Oscillometry / Q000379:methods; D011108:Polymers / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D014783:Viscosity
chemical_list: D004798:Enzymes; D007477:Ions; D011108:Polymers; D006046:Gold; D004247:DNA; D051528:Guanylate Kinases