Model Membranes

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Over 50% of current pharmaceuticals target membrane proteins, but they represent less than 2% of known protein structures. This discrepancy is largely due to the difficulty in working with membrane proteins. In order to study membrane proteins in vitro, a membrane mimetic must be used. This membrane mimic must shield the hydrophobic transmembrane residues of the membrane protein so that it is stable and able to be studied in an aqueous environment. Several studies in the Columbus Lab aim to better characterize model membranes used to study membrane proteins. Detergents self-associate to form micelles, while detergents and lipids associate to form bicelles. The classically described bicelle contains a central disk-shaped lipid bilayer encircled by a rim of detergents which screen the hydrophobic lipid tails from water. We study the morphology and detergent-lipid segregation in bicelles using SAXS, SANS, MD, and fluorescence anisotropy. 

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DHPC

detergent

DMPC

lipid

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Ideal bicelle

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Mixed micelle/bicelle