Accumulation and separation of membrane-bound proteins using hydrodynamic forces

Research output: Contribution to journalArticle

Abstract

The separation of molecules residing in the cell membrane remains a largely unsolved problem in the fields of bioscience and biotechnology. We demonstrate how hydrodynamic forces can be used to both accumulate and separate membrane-bound proteins in their native state. A supported lipid bilayer (SLB) was formed inside a microfluidic channel with the two proteins streptavidin (SA) and cholera toxin (CT) coupled to receptors in the lipid bilayer. The anchored proteins were first driven toward the edge of the lipid bilayer by hydrodynamic forces from a flowing liquid above the SLB, resulting in the accumulation of protein molecules at the edge of the bilayer. After the concentration process, the bulk flow of liquid in the channel was reversed and the accumulated proteins were driven away from the edge of the bilayer. Each type of protein was found to move at a characteristic drift velocity, determined by the frictional coupling between the protein and the lipid bilayer, as well as the size and shape of the protein molecule. Despite having a similar molecular weight, SA and CT could be separated into monomolecular populations using this approach. The method also revealed heterogeneity among the CT molecules, resulting in three subpopulations with different drift velocities. This was tentatively attributed to multivalent interactions between the protein and the monosialoganglioside G(M1) receptors in the lipid bilayer.

Details

Authors
External organisations
  • Chalmers University of Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry

Keywords

  • Cholera Toxin, G(M1) Ganglioside, Hydrodynamics, Lipid Bilayers, Membrane Proteins, Microfluidic Analytical Techniques, Protein Binding, Streptavidin, Journal Article, Research Support, Non-U.S. Gov't
Original languageEnglish
Pages (from-to)604-11
Number of pages8
JournalAnalytical Chemistry
Volume83
Issue number2
Publication statusPublished - 2011 Jan 15
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes