Elastic modulus of suspended purple membrane measured by atomic force microscopy

Journal article

We have probed the mechanical properties of purple membrane (PM) in a physiological environment using the atomic force microscope (AFM). By suspending PM over nano-trenches, the elastic properties of PM can be evaluated free from the interaction with the substrate. Force-displacement curves were obtained on the suspended membrane and the data was compared to that of a simple model of a thin film over a trench. By fitting the data to the model, the elastic modulus of PM was estimated to be 8 MPa. When the membrane is repeatedly indented, we observed a change in the force-distance data consistent with damage to the two-dimensional crystal of PM. In this paper we demonstrate that the AFM allows us to evaluate the mechanics of biological membranes in their native conditions. © 2008 Elsevier B.V. All rights reserved.

Authors: Siitonen, A; Sumitomo, K; Ramanujan, C; Shinozaki, Y; Kasai, N

• Publication status: Published
• Journal: APPLIED SURFACE SCIENCE
• Volume: 254
• Issue: 23
• Pages: 7877-7880
• Publication date: 2008-09-30
• DOI: 10.1016/j.apsusc.2008.03.009
• ISSN: 0169-4332
• Language: English
• Keywords: scanning probe microscopy; nanobiotechnology; membrane protein; elastic modulus