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C. Ted Lee, Jr.
tedlee@usc.edu
Assistant Professor
Ph.D., Chemical Engineering, Texas, Austin
M.S., Chemical Engineering, Clemson University, 1996
B.S., Chemical Engineering, Clemson University, 1994
My group conducts research in the broad area of responsive surfactant systems, namely systems that are tunable through manipulation of some external variable (e.g., light, pressure, etc.). Surfactants inherently self assemble into a variety of nanometer-scale structures, thus, using responsive surfactants allows one the remarkable ability to control the type and size of the resultant structure with nanometer precision.
Contact Information
Mork Family Department of Chemical Engineering and Materials Science
University of Southern California
925 Bloom Walk, HED 207
Los Angeles, CA 90089-1211
Phone: (213) 740-2066
Fax: (213) 740-8053
In the News: Little Big Science
Photocontrol of protein folding
The photocontrolled binding of light-sensitive surfactants onto proteins is being investigated as a means to control protein folding with light irradiation. These photosensitive surfactants undergo a reversible photoisomerization upon exposure to the appropriate wavelength of light, with the visible-light form of the surfactant being more hydrophobic than the UV-light form. As a consequence, the visible-light form exhibits enhanced binding to the hydrophobic domains of the protein compared to the UV-light form of the surfactant. Light scattering and small-angle neutron scattering have recently revealed that this light-directed (i.e., reversible) surfactant binding causes bovine serum albumin (BSA) to unfold, with an increase in the protein elongation in solution from 90 to 250 Ã…. The more hydrophobic trans form of the surfactant causes a greater degree of protein unfolding than the cis form, therefore providing for a means to reversibly control protein folding with light. This ability to induce changes in protein structure with simple light exposure could have profound ramifications in drug discovery, where specific drug forms exhibit enhanced activity. Furthermore, the completion of the human genome project immediately gives rise to the “human proteome project”, where rapid characterization of the large number of proteins that result from specific genetic sequences could be aided through photocontrolled protein crystallization. All told, this project could provide insight and novel treatments for ailments that occur because of incorrect protein folding (e.g., Alzheimer's and mad cow diseases), while extension of this phenomenon to other biological entities (e.g., DNA) may one day produce anti-cancer remedies via light-induced gene transfection.
Recent Publications
Lee, C.T.; Smith, K.A.; Hatton, T.A. “Photoreversible Gelation in Mixtures of Hydrophobically-Modified Polyelectrolytes and Photoresponsive Surfactants ” Langmuir 2002, to be submitted
Lee, C.T.; Hatton, T.A. “Photocontrol of Protein Folding in the Presence of Photoresponsive Surfactants as Studied by Small-Angle Neutron Scattering ” J. Phys. Chem. B 2002, in preparation.
Lee, C.T.; Ryoo, W.; Webber, S.E.; Johnston, K.P. “Carbon Dioxide-in-Water Microemulsions” J. Am. Chem. Soc. 2003, 125, 3181.
Lee, C.T.; Cochran, H.D.; Wignall, G.D.; Johnston, K.P. “Droplet Interactions in Water-in-Carbon Dioxide Microemulsions Near the Critical Point: A Small-Angle Neutron Scattering Study” J. Phys. Chem. B 2001, 105, 3540.
Lee, C.T.; Cochran, H.D.; Wignall, G.D.; Johnston, K.P. “Formation of Water-in-Carbon Dioxide Microemulsions with a Cationic Surfactant: A Small-Angle Neutron Scattering Study” J. Phys. Chem. B 2000, 104, 11094.
Lee, C.T.; Bhargava, P.A.; Johnston, K.P. “Percolation Phenomenon in Concentrated Water-in-Carbon Dioxide Microemulsions” J. Phys. Chem. B 2000, 104, 4448.
Lee, C.T.; Psathas, P.A.; Johnston, K.P. “Water-in-Carbon Dioxide Emulsions: Formation and Stability” Langmuir 1999, 15, 6781. Nagashima, K.;
Lee, C.T.; Johnson, C.S.; Johnston, K.P. “NMR studies of water transport and proton exchange in water-in-carbon dioxide microemulsions” J. Phys. Chem. B 2002, 107, 1962.
Yeung, L.; Lee, C.T.; Johnston, K.P.; Crooks, R.M. “Catalysis in supercritical CO2 using dendrimer-encapsulated palladium nanoparticles” Chem. Comm. 2001, 21, 2290.
Psathas, P.A.; da Rocha, S.R.P.; Lee, C.T.; Johnston, K.P. “Water-in-Carbon Dioxide Emulsions with PDMS-based Block Copolymer Ionomers” Ind. Eng. Chem. Res. 2000, 39, 2655.
Jacobson, G.B.; Lee, C.T.; Johnston, K.P.: Tumas, W. “Enhanced Catalyst Reactivity and Separations Using Water/Carbon Dioxide Emulsions” J. Am. Chem. Soc. 1999, 121, 11902. J
acobson, G.B.; Lee, C.T.; Johnston, K.P. “Organic Synthesis in Water/Carbon Dioxide Microemulsions” J. Org. Chem. 1999, 64, 1201.
Jacobson, G.B.; Lee, C.T.; da Rocha, S.R.P.; Johnston, K.P. “Organic Synthesis in Water/Carbon Dioxide Emulsions” J. Org. Chem. 1999, 64, 1207.
Holmes, J.D.; Ziegler, K.J.; Audriani, M.; Lee, C.T.; Bhargava, P.A.; Steytler, D.C.; Johnston, K.P. “Buffering the Aqueous Phase pH in Water-in-CO2 Microemulsions” J. Phys. Chem. B. 1999, 103, 5703
Book Chapters
Johnston, K. P.; Holmes, J.; Jacobson, G.; Lee, C. T., Li, G.; Yates, M. Z. "Reactions and Synthesis in Microemulsions and Emulsions in Carbon Dioxide" In Reactions and Synthesis in Surfactant Systems, Texter, J., Ed., Marcel Dekker: New York, 2001.
Johnston, K. P.; Jacobson, G. B.; Lee, C. T.; Meredith, C.; Da Rocha, S. R. P.; Yates, M. Z.; DeGrazia, J.; Randolph, T. W. "Microemulsions, Emulsions, and Latexes in Supercritical Fluids" In Chemical Synthesis in Supercritical Fluids, Jessop, P., Leitner, W. Ed., Wiley-VCH Publishers: Weinheim, 1999.
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