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Schönfeldová T, Okur HI, Vezočnik V, Iacovache I, Cao C, Dal Peraro M, Maček P, Zuber B, Roke S. Ultrasensitive Label-Free Detection of Protein-Membrane Interaction Exemplified by Toxin-Liposome Insertion. J Phys Chem Lett 2022; 13:3197-3201. [PMID: 35377651 PMCID: PMC9014461 DOI: 10.1021/acs.jpclett.1c04011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Measuring the high-affinity binding of proteins to liposome membranes remains a challenge. Here, we show an ultrasensitive and direct detection of protein binding to liposome membranes using high throughput second harmonic scattering (SHS). Perfringolysin O (PFO), a pore-forming toxin, with a highly membrane selective insertion into cholesterol-rich membranes is used. PFO inserts only into liposomes with a cholesterol concentration >30%. Twenty mole-percent cholesterol results in neither SHS-signal deviation nor pore formation as seen by cryo-electron microscopy of PFO and liposomes. PFO inserts into cholesterol-rich membranes of large unilamellar vesicles in an aqueous solution with Kd = (1.5 ± 0.2) × 10-12 M. Our results demonstrate a promising approach to probe protein-membrane interactions below sub-picomolar concentrations in a label-free and noninvasive manner on 3D systems. More importantly, the volume of protein sample is ultrasmall (<10 μL). These findings enable the detection of low-abundance proteins and their interaction with membranes.
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Affiliation(s)
- T. Schönfeldová
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - H. I. Okur
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Department
of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - V. Vezočnik
- Department
of Biology, Biotechnical Faculty, University
of Ljubljana, Jamnikarjeva 101, Ljubljana 1000, Slovenia
| | - I. Iacovache
- Institute
of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - C. Cao
- Institute
of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - M. Dal Peraro
- Institute
of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - P. Maček
- Department
of Biology, Biotechnical Faculty, University
of Ljubljana, Jamnikarjeva 101, Ljubljana 1000, Slovenia
| | - B. Zuber
- Institute
of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - S. Roke
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Institute
of Materials Science (IMX) and Lausanne Centre for Ultrafast Science
(LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
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