title: Electric-field-stimulated protein mechanics.
abstract: The internal mechanics of proteins-the coordinated motions of amino acids and the pattern of forces constraining these motions-connects protein structure to function. Here we describe a new method combining the application of strong electric field pulses to protein crystals with time-resolved X-ray crystallography to observe conformational changes in spatial and temporal detail. Using a human PDZ domain (LNX2PDZ2) as a model system, we show that protein crystals tolerate electric field pulses strong enough to drive concerted motions on the sub-microsecond timescale. The induced motions are subtle, involve diverse physical mechanisms, and occur throughout the protein structure. The global pattern of electric-field-induced motions is consistent with both local and allosteric conformational changes naturally induced by ligand binding, including at conserved functional sites in the PDZ domain family. This work lays the foundation for comprehensive experimental study of the mechanical basis of protein function.
authors.affiliation: Green Center for Systems Biology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.
authors.forename: Doeke R
authors.initials: DR
authors.lastname: Hekstra
authors.affiliation: Green Center for Systems Biology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.
authors.forename: K Ian
authors.initials: KI
authors.lastname: White
authors.affiliation: Green Center for Systems Biology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Socolich
authors.affiliation: Center for Advanced Radiation Sources, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Henning
authors.affiliation: Center for Advanced Radiation Sources, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Vukica
authors.initials: V
authors.lastname: Šrajer
authors.affiliation: Green Center for Systems Biology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.|Departments of Biophysics and Pharmacology, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.
authors.forename: Rama
authors.initials: R
authors.lastname: Ranganathan
mesh_terms: D000494:Allosteric Regulation; D001696:Biomechanical Phenomena; D018360:Crystallography, X-Ray / Q000379:methods*; D004560:Electricity; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D009068:Movement; D054731:PDZ Domains; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D008024:Ligands; D011506:Proteins