Research in our lab focuses on understanding the lateral organization and dynamics of lipid molecules within cell membranes. Related work concentrates on monitoring interactions of biomolecules (proteins and polymers) with the cell and following subsequent changes to the membrane. The outer leaflet of the cell is modeled by a lipid monolayer at the air/water interface. To measure material and structural properties of the monolayer, various biophysical techniques ranging from fluorescence microscopy to two-dimensional pressure vs. area isotherms to x-ray scattering are used. Current projects include: 1) determination of the role of lipid molecular shape and charge on the formation of “lipid rafts” or ordered regions in the membrane, 2) characterization of wrinkling and folding in skin cell models, 3) short and long-term effects of exposure to nanoparticles on membrane structure and stability.
EY Chi, SL Frey, A Winans, KLH Lam, K Kjaer, J Majewski, and KYC Lee. Amyloid-beta fibrillogenesis seeded by interface-induced peptide misfolding and self-assembly. Biophysical Journal, 98 (2010) 2290-2298.
SL Frey, L Pocivavsek, AJ Waring, FJ Walther, JM Hernandez-Juviel, P Ruchala, and KYC Lee. The functional importance of N-terminal insertion sequence of lung surfactant protein, SP-B. American Journal of Physiology – Lung Cellular and Molecular Physiology, 298 (2010) L335-L347.
MK Ratajczak, EY Chi, SL Frey, KD Cao, L Hawk, J Majewski, K Kjaer, and KYC Lee. Ordered nanoclusters in lipid:cholesterol membranes. Physical Review Letters, 103 (2009) 028103.
L Pocivavsek, SL Frey, K Krishan, K Gavrilov, P Ruchala, AJ Waring, FJ Walther, M Dennin, TA Witten and KYC Lee. Lateral Stress Relaxation and Collapse in Lipid Monolayers. Soft Matter, 4 (2008) 2019-2029.