Assistant Professor of Chemistry

Ph.D., 2001, Max Planck Institute for Polymer Research/Johannes Gutenberg University of Mainz

250N Chemistry 1973 Wing
Tel: 215-573-7539 (office) 
Fax: 215-898-6242
Email: baumgart@sas.upenn.edu

Among the most fascinating biological structures found in nature are biomembranes that surround cellular systems and intracellular organelles. These membranes function as barriers between cellular compartments, as transport vehicles and regulators, and contain machineries important for biological functioning. Cell biology has traditionally focused on examining protein / protein interactions. However, the physical chemistry and mechanical properties of the lipid bilayer matrix are tightly coupled to the functioning of membrane associated proteins in ways that are largely unknown. This provides rich opportunities for exciting and important new insights.

We examine lipid / protein interactions in biological and model membranes by laser scanning confocal microscopy techniques. Membrane domain formation is studied in a temperature-dependent fashion. We are particularly interested in establishing the molecular details that determine how membrane proteins redistribute between lipid domains to understand how lipid / protein interactions influence membrane functioning. Furthermore, we use mechanical methods to deform membranes and examine membrane curvature-dependent lipid / protein interactions that include redistribution in membrane curvature gradients, curvature-dependent binding of peripheral membrane proteins, and we study protein geometries dependent on lipid membrane curvature.

Selected Publications

Baumgart, T., S. Das, W.W. Webb and J.T. Jenkins (2005) Membrane elasticity in giant vesicles with fluid phase coexistence. Biophysical Journal 89(2):1067-1080.

Hammond, A.T., F.A. Heberle, T. Baumgart, D. Holowka, B. Baird and G.W. Feigenson (2005) Crosslinking a lipid raft component triggers liquid ordered-liquid disordered phase separation in model plasma membranes. PNAS 102(18):6320-6325.

Korlach J., T. Baumgart, G.W. Feigenson and W.W. Webb Detection of motional heterogeneities in lipid bilayer membranes by dual probe fluorescence correlation spectroscopy. Biochimica et Biophysica Acta 1668:158-163.

Baumgart T., S.T. Hess and W.W. Webb (2003) Imaging coexisting fluid domains in biomembrane models coupling curvature and line tension. Nature 425:821-824.

Baumgart T., M. Kreiter, H. Lauer, R. Naumann, G. Jung, A. Jonczyk, A. Offenhausser and W. Knoll (2003) Fusion of small unilamellar vesicles onto laterally mixed self-assembled monolayers of thiolipopeptides. Journal of Colloid and Interface Science 258:298-309.