Comparison of [corrected] actin- and glass-supported phospholipid bilayer diffusion coefficients

Sarah M Sterling; Ryan Dawes; Edward S Allgeyer; Sharon L Ashworth; David J Neivandt

doi:10.1016/j.bpj.2015.02.033

Comparison of [corrected] actin- and glass-supported phospholipid bilayer diffusion coefficients

Biophys J. 2015 Apr 21;108(8):1946-53. doi: 10.1016/j.bpj.2015.02.033.

Authors

Sarah M Sterling¹, Ryan Dawes², Edward S Allgeyer³, Sharon L Ashworth⁴, David J Neivandt⁵

Affiliations

¹ Department of Chemical and Biological Engineering, University of Maine, Orono, Maine; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine.
² School of Biology and Ecology, University of Maine, Orono, Maine.
³ Department of Physics and Astronomy, University of Maine, Orono, Maine.
⁴ Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine; School of Biology and Ecology, University of Maine, Orono, Maine.
⁵ Department of Chemical and Biological Engineering, University of Maine, Orono, Maine; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine. Electronic address: dneivandt@umche.maine.edu.

Abstract

The formation of biomimetic lipid membranes has the potential to provide insights into cellular lipid membrane dynamics. The construction of such membranes necessitates not only the utilization of appropriate lipids, but also physiologically relevant substrate/support materials. The substrate materials employed have been shown to have demonstrable effects on the behavior of the overlying lipid membrane, and thus must be studied before use as a model cushion support. To our knowledge, we report the formation and investigation of a novel actin protein-supported lipid membrane. Specifically, inner leaflet lateral mobility of globular actin-supported DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) bilayers, deposited via the Langmuir-Blodgett/Langmuir Schaefer methodology, was investigated by z-scan fluorescence correlation spectroscopy across a temperature range of 20-44°C. The actin substrate was found to decrease the diffusion coefficient when compared to an identical membrane supported on glass. The depression of the diffusion coefficient occurred across all measured temperatures. These results indicated that the actin substrate exerted a direct effect on the fluidity of the lipid membrane and highlighted the fact that the choice of substrate/support is critical in studies of model lipid membranes.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Actins / chemistry*
Diffusion
Dimyristoylphosphatidylcholine / chemistry
Glass / chemistry*
Lipid Bilayers / chemistry*

Substances

Actins
Lipid Bilayers
Dimyristoylphosphatidylcholine