title: Two barriers or not? Dynamic force spectroscopy on the integrin α7β1 invasin complex.
abstract: Dynamic force spectroscopy was used to test force-induced dissociation of the complex between the integrin α7β1 and the bacterial protein invasin. Both proteins were used in truncated forms comprising the respective binding sites. Using the biomembrane force-probe, the bond system was exposed to 14 different loading rates ranging from 18 pN/s to 5.3 nN/s. At each rate, bond rupture spectra were collected. Median forces ranged from 8 to 72 pN. These showed two linear regimes when plotted against the logarithm of the force-loading rate. However, a statistical analysis of the full rupture force spectra including the detection limits of the setup showed that all measured data are well described by dissociation over a single barrier.
authors.affiliation: MEMPHYS-Center for Biomembrane Physics, Institute of Physics and Chemistry, University of Southern Denmark, Odense, Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Boye
authors.affiliation: MEMPHYS-Center for Biomembrane Physics, Institute of Physics and Chemistry, University of Southern Denmark, Odense, Denmark; Department of Physics, Jagiellonian University, Cracow, Poland; Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ligezowska
authors.affiliation: Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Eble
authors.affiliation: Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hoffmann
authors.affiliation: MEMPHYS-Center for Biomembrane Physics, Institute of Physics and Chemistry, University of Southern Denmark, Odense, Denmark.
authors.forename: Beate
authors.initials: B
authors.lastname: Klösgen
authors.affiliation: Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany. Electronic address: r.merkel@fz-juelich.de.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Merkel
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D016023:Integrins / Q000737:chemistry / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D018829:Adhesins, Bacterial; D016023:Integrins; C053476:invasin, Yersinia; C082908:integrin alpha7beta1