title: Quantitative time-resolved measurement of membrane protein-ligand interactions using microcantilever array sensors.
abstract: Membrane proteins are central to many biological processes, and the interactions between transmembrane protein receptors and their ligands are of fundamental importance in medical research. However, measuring and characterizing these interactions is challenging. Here we report that sensors based on arrays of resonating microcantilevers can measure such interactions under physiological conditions. A protein receptor--the FhuA receptor of Escherichia coli--is crystallized in liposomes, and the proteoliposomes then immobilized on the chemically activated gold-coated surface of the sensor by ink-jet spotting in a humid environment, thus keeping the receptors functional. Quantitative mass-binding measurements of the bacterial virus T5 at subpicomolar concentrations are performed. These experiments demonstrate the potential of resonating microcantilevers for the specific, label-free and time-resolved detection of membrane protein-ligand interactions in a micro-array format.
authors.affiliation: School of Physics and Centre for Research on Adaptive Nanostructures and Nanodevices, Naughton Institute, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Braun
authors.forename: Murali Krishna
authors.initials: MK
authors.lastname: Ghatkesar
authors.forename: Natalija
authors.initials: N
authors.lastname: Backmann
authors.forename: Wilfried
authors.initials: W
authors.lastname: Grange
authors.forename: Pascale
authors.initials: P
authors.lastname: Boulanger
authors.forename: Lucienne
authors.initials: L
authors.lastname: Letellier
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Lang
authors.forename: Alex
authors.initials: A
authors.lastname: Bietsch
authors.forename: Christoph
authors.initials: C
authors.lastname: Gerber
authors.forename: Martin
authors.initials: M
authors.lastname: Hegner
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001435:Bacteriophages; D015374:Biosensing Techniques / Q000295:instrumentation*; D029968:Escherichia coli Proteins / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D055550:Protein Stability; D011510:Proteolipids / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D013997:Time Factors
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C050900:FhuA protein, E coli; D008024:Ligands; D008565:Membrane Proteins; D011510:Proteolipids; D011956:Receptors, Cell Surface; C020485:proteoliposomes