Scanning near-field IR microscopy of proteins in lipid bilayers

• Published in: Physical chemistry chemical physics : PCCP 2011-12, Vol.13 (48), p.21432-21436
• Main Authors: Ballout, Fouad, Krassen, Henning, Kopf, Ilona, Ataka, Kenichi, Bründermann, Erik, Heberle, Joachim, Havenith, Martina
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Electron Transport Complex IV - chemistry; Electron Transport Complex IV - metabolism; Exact sciences and technology; General and physical chemistry; Lipid Bilayers - chemistry; Lipid Bilayers - metabolism; Membranes; Microscopy, Atomic Force; Protein Binding; Spectroscopy, Near-Infrared
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/c1cp21512d

We use infrared near-field microscopy to chemically map the morphology of biological matrices. The investigated sample is built up from surface-tethered membrane proteins (cytochrome c oxidase) reconstituted in a lipid bilayer. We have carried out infrared near-field measurements in the frequency range between 1600 and 1800 cm −1 . By simultaneously recording the topography and chemical fingerprint of the protein-tethered lipid bilayer with a lateral resolution of 80 nm × 80 nm, we were able to probe locally the chemical signature of this membrane and to provide a local map of its surface morphology. Scattering near-field IR microscopy of membrane proteins reconstituted into a lipid bilayer imaged with a spatial resolution of less than 80 nm.