title: Cytoskeletal mechanics in adherent human airway smooth muscle cells: probe specificity and scaling of protein-protein dynamics.
abstract: We probed elastic and loss moduli in the adherent human airway smooth muscle cell through a variety of receptor systems, each serving as a different molecular window on cytoskeletal dynamics. Coated magnetic microbeads were attached to the cell surface via coating-receptor binding. A panel of bead coatings was investigated: a peptide containing the sequence RGD, vitronectin, urokinase, activating antibody against beta(1)-integrin, nonactivating antibody against beta(1)-integrin, blocking antibody against beta(1)-integrin, antibody against beta(1)-integrin, and acetylated low-density lipoprotein. An oscillatory mechanical torque was applied to the bead, and resulting lateral displacements were measured at baseline, after actin disruption by cytochalasin D, or after contractile activation by histamine. As expected, mechanical moduli depended strongly on bead type and bead coating, differing at the extremes by as much as two orders of magnitude. In every case, however, elastic and loss moduli increased with frequency f as a weak power law, f( x-1). Moreover, with few exceptions, data could be scaled such that elastic and frictional responses depended solely on the power law exponent x. Taken together, these data suggest that power law behavior represents a generic feature of underlying protein-protein dynamics.
authors.affiliation: Physiology Program, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115. mpuigdem@hsph.harvard.edu
authors.forename: Marina
authors.initials: M
authors.lastname: Puig-de-Morales
authors.forename: Emil
authors.initials: E
authors.lastname: Millet
authors.forename: Ben
authors.initials: B
authors.lastname: Fabry
authors.forename: Daniel
authors.initials: D
authors.lastname: Navajas
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: James P
authors.initials: JP
authors.lastname: Butler
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fredberg
mesh_terms: D000107:Acetylation; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000502:physiology*; D004548:Elasticity; D006801:Humans; D039641:Integrin beta Chains / Q000378:metabolism; D008024:Ligands; D008077:Lipoproteins, LDL / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008954:Models, Biological; D032389:Myocytes, Smooth Muscle / Q000502:physiology* / Q000648:ultrastructure; D009842:Oligopeptides / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D013314:Stress, Mechanical; D014132:Trachea / Q000502:physiology; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D014783:Viscosity; D019096:Vitronectin / Q000378:metabolism
chemical_list: D039641:Integrin beta Chains; D008024:Ligands; D008077:Lipoproteins, LDL; D009842:Oligopeptides; D019096:Vitronectin; C047981:arginyl-glycyl-aspartic acid; D014568:Urokinase-Type Plasminogen Activator