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.
Additional Information
© 2009 Macmillan Publishers Limited. Published online: 18 January 2009. We thank A. Engel for the use of facilities for protein reconstitution at the Biozentrum, University of Basel, and M. Chami for fruitful discussions. We thank D. Mathys, M. Du¨ggelin and M. Du¨rrenberger for their help with the SEM analysis. Financial and general support is acknowledged from Swiss National Science Foundation (NCCR Nanoscale Science), the Commission for Technology and Innovation (CTI) (TOPNANO21), the European Learning and Teaching Mobility Regio Network, the G.H. Endress Foundation, the Novartis Foundation and the Science Foundation Ireland CSET programme. M.K.G. thanks the Swiss National Science Foundation and the Novartis Foundation for a research fellowship. T.B. and M.H. conceived and designed the experiments; T.B. and M.K.G. performed the experiments; T.B., M.K.G., W.G. and M.H. analysed the data; P.B. and L.L. contributed expertise in membrane proteins and phages; A.B. and T.B. were responsible for the ink-jet spotting of the membrane proteins; T.B., N.B., W.G., H.P.L. and M.H. co-wrote the paper. All authors discussed the results and commented on the manuscript.Additional details
- Eprint ID
- 14220
- Resolver ID
- CaltechAUTHORS:20090514-145726853
- Swiss National Science Foundation
- TOPNANO21
- Commission for Technology and Innovation (CTI)
- European Learning and Teaching Mobility Regio Network
- G.H. Endress Foundation
- Novartis Foundation
- Science Foundation Ireland
- Created
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2009-08-14Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field