271531 Separation and Characterization of Raft Associated Membrane Species Using a Patterned Supported Lipid Bilayer

Tuesday, October 30, 2012: 2:20 PM
404 (Convention Center )
Mark J. Richards1, Ling Chao2 and Susan Daniel1, (1)Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, (2)Chemical Engineering, National Taiwan University, Taipei, Taiwan

The role of lipid rafts is important in understanding cell processes and disease states; however, identifying the key components of these lipid domains is difficult and impedes research progress. Here we present a new platform to sort, separate, and characterize membrane-bound molecules based on their affinity for raft phase domains using a heterogeneous supported lipid bilayer (SLB) consisting of patterned lipid raft and non-raft domains.  Adjacent SLBs consisting of liquid-ordered and liquid-disordered phases are formed in predefined locations. Membrane-bound biomolecules loaded into the device are convected laterally in the two-dimensional plane along the heterogeneous supported bilayer by a shear force induced from hydrodynamic flow of the bulk aqueous phase. During axial convection, the membrane-bound biomolecules diffuse within the 2-D heterogeneous bilayer plane, partitioning into their preferred lipid phase. Patterns for the lipid phases are designed to facilitate the sorting and collection of separated species. The main advantages of this new method over existing methods used to identify and assay raft species include separating membrane species within a membrane environment, near physiological conditions, and without artifacts associated with detergent, high salt, or alkaline pH. These criteria are particularly crucial to the separation of lipid-linked proteins and transmembrane proteins to avoid denaturation. This new capability to separate membrane-bound species near native conditions based on affinity for certain lipid phases can be used to identify intrinsic membrane raft residents, characterize how post-translational modifications shift the affinity of analogs to a particular lipid phase and dynamically observe the effect of membrane composition on membrane species behavior.

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See more of this Session: Advances In Bioseparations
See more of this Group/Topical: Separations Division