J. Kent Blasie

Photo: 
First Name: 
J. Kent
Last Name: 
Blasie
Official Title: 
Walter H. & Leonore C. Annenberg Professor in the Natural Sciences

Biological, Chemical Physics and Physical Chemistry

Contact Information
Office Location: 
2003 Vagelos, Lab: Vagelos 2170, 2190, 2210-2211, 2230-2231 and 2240
Email: 
jkblasie@sas.upenn.edu
Phone: 
(215) 898-6208
Education: 
  • B.S. University of Michigan (1964)
  • Ph.D. University of Michigan (1968)
  • USPHS Career Development Award (1971-76)
  • Guest Biophysicist, Brookhaven National Laboratory (1973-present)
  • Chairman, Department of Chemistry (1983-1986)
  • Director, Biostructures Participating Research Team, National Synchrotron Light Source, Brookhaven National Laboratory (1985-1994)
  • Executive Committee, Complex Materials Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory (1994-present)
  • Scientific Advisory Committee & Advisory Board, Spallation Neutron Source, Oak Ridge National Laboratory (1997-2006)
  • Executive Committee, Cold Neutrons in Biology and Technology Team, National Institutes of Standards and Technology (1998-2006)
  • Director, Complex Materials Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory (2001-present)
Research Interests: 

Our research program falls into two areas, namely nano-scale materials science and fundamental biophysics (or biophysical chemistry). The materials science effort is directed toward the development of novel electro-optical devices, both single particle and 2-D to 3-D ensemble based, utilizing the unique microscopic properties of designed cofactor-artificial peptide complexes. The cofactors are based primarily on extended conjugated chromophores designed to exhibit light-induced electric charge transfer over large nano-scale distances and possess minimal HOMO-LUMO bandgaps. The highly stable, artificial α-helical peptides are based on n-helix bundle structural motifs designed to vectorially incorporate the cofactor within the core of the bundle and to order the assembly of the peptide-cofactor complexes at the liquid-gas, solid-liquid or solid-gas interface. Ensembles of these complexes have potential for both photovoltaic devices applications relevant to solar energy conversion and non-linear optical device applications relevant to broad-band communications. The structures and properties of both the isolated complexes and the ensembles thereof are determined by cutting-edge techniques, including molecular dynamics simulation, synchrotron x-ray and cold neutron scattering, and polarized CW and transient spectroscopies. The biophysics effort is directed toward understanding the mechanism of volatile general anesthetic action on membrane ion channels. To better access the physical chemistry of the anesthetic-protein interaction, we are utilizing artificial membrane ion channels based on an amphiphilic 4-helix bundle motif, the hydrophilic domain designed to possess the anesthetic binding cavity and the hydrophobic domain designed as a membrane-spanning cation channel. The same techniques mentioned above are utilized to probe the nature of the anesthetic-peptide interaction and its effect on the conformation of the ion channel domain. Future work will also be directed toward understanding the mechanism of electro-mechanical coupling in the substantially more complex, natural voltage-gated ion channels under the control of the applied transmembrane electrochemical potential. These studies will employ cutting-edge time-resolved synchrotron x-ray and cold neutron scattering techniques coupled with molecular dynamics simulation, and will lead to the investigation of the effects of anesthetic binding on this mechanism. All of the work mentioned above involves both extensive collaborations with other faculty in the Department, at Penn, and elsewhere, as well as experimental work at the National Laboratories on a regular basis.

Figure Legend #1: An instantaneous configuration from a molecular dynamics simulation of the structure of an extended conjugated chromophore (a butadiyne-bridged Zn-porphyrin dimer: red/yellow) incorporated into the core of the hydrophilic domain of an amphiphilic 4-helix bundle peptide (green ribbon representation) and vectorially-oriented at the water-octane (gray-pink) interface. The time-averaged structure of the chromophore-peptide complex within a monolayer ensemble at the interface has been determined experimentally. The designed coiled-coil structure of the 4-helix bundle induces a twist in the chromophore that is key to optimizing its non-linear optical polarizability.

Figure Legend #2: Instantaneous configurations from molecular dynamics simulations of the structures of a computationally designed, model anesthetic-binding membrane ion channel vectorially-oriented at the water-octane interface (water/octane not shown; see Figure 1). The hydrophilic domain (blue ribbon representation) of the amphiphilic 4-helix bundle peptide contains the anesthetic-binding cavity with the volatile anesthetic halothane (CPK representation) in the cavity shown on the right-side, with the ion channel hydrophobic domain (red ribbon representation). The helices are relatively straight and un-coiled in the side-on view (upper), as more readily seen in the end-on view shown below. Removal of the anesthetic from the cavity is seen to induce a coiled-coil structure extending from the cavity into the ion channel hydrophobic domain, shown in the side-on and end-on views on the left side. Importantly, this anesthetic-dependent conformational change depends upon the amino acid composition of the cavity. Experimental verification of these predictions from the computational design and molecular dynamics simulations are underway.

Selected Publications: 

 

Gupta, S., Dura, J., Freites, A. Tobias, D. and Blasie, J.K. Structural characterization of the voltage sensor domain and voltage-gated K+-channel vectorially-oriented within a single bilayer membrane at the solid/vapor and solid/liquid interfaces via neutron interferometry. Submitted.

 

Koo, J., Park, J., Tronin, A., Zhang, R., Krishnan, V., Strzalka, J., Kuzmenko, I., Therien, M.J. and Blasie, J.K. Acentric 2-D Ensembles of D-br-A Electron-Transfer Chromophores via Vectorial Orientation within Amphiphilic n-Helix Bundle Peptides for Photovoltaic Device Applications. Langmuir, 28: (6), pp 3227-3238

http://pubs.acs.org/doi 

 

Gupta, S., Liu, J., Strzalka, J. and Blasie, J.K. (2011) Profile Structures of the VSD and KvAP Channel Vectorially-Oriented in Single Membranes at Solid-Vapor or Solid-Liquid Interfaces via X-ray Reflectivity. Phys. Rev. E. 84(3): 031911-1-15. 

http://pre.aps.org/

 

Korendovych, I., Senes, A., Kim, Y.H., Lear, J., Fry, H.C., Therien, M.J., Blasie, J.K., Walker, F.A. and DeGrado, W.F. (2010) De Novo Design and Molecular Assembly of a Transmembrane Diporphyrin-Binding Protein Complex. J. Am. Chem. Soc. Comm. 132: 15516-15518. 

http://pubs.acs.org/Volume=132

 

Gonella, G., Dai, H.-L., Fry, H. C., Therien, M. J., Krishnan, V., Tronin, A. and Blasie, J.K. (2010) Control of the Orientational Order and Nonlinear Optical Response of the "Push-Pull" Chromophore RuPZn via Specific Incorporation into Densely-Packed Monolayer Ensembles of an Amphiphilic 4-Helix Bundle Peptide: Second Harmonic Generation at High Chromophore Densities. J. Am. Chem. Soc. 132 (28): 9693–9700. 

http://pubs.acs.org/Volume=132 (28) 

 

Krishnan, V., Tronin, A., Strzalka, J., Fry, H.C., Therien, M.J. and Blasie, J.K. (2010) Control of the Orientational Order and Nonlinear Optical Response of the “Push-Pull” Chromophore RuPZn via Specific Incorporation into Densely-Packed Monolayer Ensembles of an Amphiphilic 4-Helix Bundle Peptide: Characterization of the Cofactor-Peptide Complex in Monolayer Ensembles. J. Am. Chem. Soc. 132(32):11083-11092. 

http://pubs.acs.org/Volume=132 (32) 

 

Krishnan, V., Strzalka, J., Liu, J., Liu, C., Kuzmenko, I., Gog, T. and Blasie, J.K. (2010) Interferometric Enhancement of X-ray Reflectivity from Unperturbed Langmuir Monolayers of Amphiphiles at the Liquid-Gas Interface. Phys. Rev. E 81: 021604-1-10. 

http://pre.aps.org/abstract 

 

Zou, H. Liu, J. and Blasie, J.K. (2009) Mechanism of interaction between the volatile anesthetic halothane and a model ion channel protein: III. Molecular dynamics simulation incorporating a cyano-phenylalanine spectroscopic probe. Biophys. J. 96(10) pp. 4188 – 4199.

http://biophysj/Volume96=16

 

Liu, J., Strzalka, J., Tronin, A., Johansson, J.S. and Blasie, J.K. (2009) Mechanism of interaction between the volatile anesthetic halothane and a model ion channel protein: II. Fluorescence & vibrational spectroscopy employing a cyano-phenylalanine probe. Biophys. J. 96(10) pp. 4176 – 4187.

http://biophysj/Volume96

 

Strzalka, J., Liu, J., Tronin, A., Johansson, J.S. and Blasie, J.K. (2009) Mechanism of interaction between the volatile anesthetic halothane and a model ion channel protein: I. Structural investigations via x-ray reflectivity from Langmuir monolayers. Biophys. J. 96(10) pp. 4164 – 4175.

http://biophysj/Volume96

 

Tronin, A., Krishnan, V., Strzalka, J., Kuzmenko, I., Gog, T., Fry, C., Therien, M.J. and Blasie, J.K. (2009) Portable UV-VIS spectrometer for measuring absorbance and dichroism of Langmuir monolayers. Rev. Sci. Instru. 80(3): 033102-1-7.

http://rsi.aip.org/

 

Zou, H., Therein, M.J. and Blasie, J.K. Structure & Dynamics of an Extended Conjugated NLO Chromophore within an Amphiphilic 4-Helix Bundle Peptide by Molecular Dynamics Simulation. Submitted to J. Phys. Chem. B.

 

McAllister, K.A., Zou, H., Cockran, F.V., Bender, G.M., Senes, A., Fry, C.F., Nanda, V., Keenan, P.A., Lear, J.D., Therien, M.J., Blasie, J.K, and DeGrado, W.F. Using α-Helical Coiled-Coils to Design Nanostructured Metalloporphyrin Arrays. Submitted to Angewandte Chemie.

 

Bender, G.M., Lehmann, A., Zou, H., Cheng, H., Fry, H.C., Engel, D., Therien, M.J., Blasie, J.K., Roder, H., Saven, J.G. and DeGrado, W.F. De Novo Design of a Single Chain Diphenylporphyrin Metalloprotein. J. Am. Chem. Soc. 129(35). 

http://pubs.acs.org/Volume=129

 

Zou, H., Strzalka, J. Xu, T., Tronin, A. and Blasie, J.K. (2007) 3-D Structure and Dynamics via Molecular Dynamics Simulation of a de novo Designed, Amphiphilic Heme Protein Maquette at Soft Interfaces. Phys. Chem. B 111: 1823-1833.

http://pubs.acs.org

 

Strzalka, J., Xu, T., Tronin, A., Wu, S.P., Miloradovic, I., Kuzmenko, I. Gog, T., Therien, M.J., and Blasie, J.K. (2006) Structural Studies of Amphiphilic 4-helix Bundle Peptides Incorporating Designed Extended Chromophores for Nonlinear Optical Biomolecular Materials. Nano Lett. 6(11): 2395-2405. 

http://pubs.acs.org/Volume=6

 

Xu, T., Wu, S.P., Miloradovic, I., Therien, M.J., and Blasie, J.K. (2006) Incorporation of Designed Extended Chromophores into Amphiphilic 4-helix Bundle Peptides for Nonlinear Optical Biomolecular Materials. Nano Lett. 6(11): 

http://pubs.acs.org/Volume=6(2387-2394)

 

Nordgren, C.E., Strzalka, J.W. and Blasie, J.K (2005) Structure of α-Helical Bundle Peptides Vectorially-Oriented at Soft Interfaces via Molecular Dynamics Simulations and X-ray/Neutron Scattering. Submitted to Langmuir.

 

Churbanova, I., Tronin, A., Strzalka, J.W., Gog, T., Kuzmenko, I., Johansson, J.S. and Blasie, J.K. (2006) Monolayers of a Model Anesthetic-Binding Membrane Protein: Formation, Characterization and Halothane-Binding Affinity. Biophys. J. 90: 3255-3266. 

http://www.cell.com/biophysj/Volume=90

 

Tronin, A., Xu, T. and Blasie, J.K. (2005) In situ Determination of Orientational Distributions in Langmuir Monolayers by Total Internal Reflection Fluorescence. Langmuir 21: 7760-7767.

http://dx.doi.org/

 

 

Discher, B.M., Noy, D., Strazalka, J, Ye, S., Moser, C.C., Lear, J.D., Blasie, J.K. and Dutton, P.L. (2005) Design of Amphiphilic Protein Maquettes: Controlling Assembly, Membrane Insertion, and Cofactor Interactions. Biochemistry 44:12329-12343.

http://pubs.acs.org/Volume=44

 

Ye, S., Discher, B.M., Strzalka, J.W., Xu, T., Wu, S.P., Noy, D., Kuzmenko, I., Gog, T., Therien, M.J., Dutton, P.L. and Blasie, J.K. (2005) Amphiphilic 4-Helix Bundles Designed for Light-Induced Electron Transfer Across Soft Interfaces. Nano Lett. 5(9):1658-1667.

http://dx.doi.org/

 

Ye, S., Strzalka, J., Churbanova, I.Y., Zheng, S,, Johansson, J.S. and Blasie JK. (2004) A Model Membrane Protein for Binding Volatile Anesthetics. Biophys. J. 87: 4065-4074.

http://www.cell.com/biophysj/Volume=87

 

Strzalka, J. DiMasi, E., Kuzmenko, I., Gog, T. and Blasie, J.K. (2004) Resonant X-ray Reflectivity from a Bromine-Labeled Fatty-Acid Langmuir Monolayer. Phys. Rev. E 70: 051603-1-5. 

http://pre.aps.org/abstract/PRE/v70/i5/e051603

 

Strzalka, J., Kneller, L.R., Gibney, B.R., Satija, S., Majkrzak, C.F. and Blasie, J.K. (2004) Specular Neutron Reflectivity and Structure of Artificial Protein Maquettes Vectorially Oriented at Interfaces. Phys. Rev. E. E 70: 061905-1-10. 

http://pre.aps.org/abstract/PRE/v70/i6/e061905 

 

Ye, S., Discher, B.M., Strzalka, J.W., Noy, D., Zheng, S., Dutton, P.L. and Blasie, J.K. (2004) Amphiphilic 4-Helix Bundles Designed for BioMolecular Materials Applications. Langmuir 20(14): 5897-5904.

http://dx.doi.org/

 

Blasie, J.K., Strzalka, J. and Zheng, S. (2003) Solution to the Phase Problem for Specular X-ray & Neutron Reflectivity from Thin Films on Liquid Surfaces. Phys. Rev. B 67: 224201-1--224201-8.

http://prb.aps.org/

 

Ye, S., Strzalka, J., Chen, X., Moser, C.C., Dutton, P.L. and Blasie, J.K. (2003) Assembly of a Vectorially-Oriented Four-Helix Bundle at the Air/Water Interface via Directed Electrostatic Interactions. Langmuir 19(5): 1515-1521.

http://pubs.acs.org/Vol=19

 

 

Zheng, S., Strzalka, J., Jones, D.H., Opella, S.J. and Blasie, J.K. (2003) Comparative Structural Studies of Vpu Peptides in Phospholipid Monolayers by X-ray Scattering. Biophys. J. 84(4): 2393-2415.

http://www.cell.com/Vol 84 

 

Lopez, C. F., Montal, M., Blasie, J.K., Klein, M.L. and Moore, P.B. (2002) Molecular Dynamics Investigation of Membrane-Bound Bundles of the Channel Forming Transmembrane Domain of Viral Protein U from the Human Immunodeficiency Virus HIV. Biophys. J. 83(3): 1259-1267.

http://biophysj/ Volume83

 

Nordgren, E., Tobias, D.J., Klein, M.L. and Blasie, J.K. (2002) Molecular Dynamics Simulations of a Hydrated Protein Vectorially-Oriented at Hydrophobic vs. Hydrophilic Soft Surfaces. Biophys. J. 83(6): 2906-2917.

http://www.cell.com/biophysj/Volume=83

 

Tronin, A., Edwards, A.M., Wright, W.W., Vanderkooi, J.M. and Blasie, J.K. (2002) Orientational Distributions for Cytochrome c on Polar & Nonpolar Soft Surfaces by Polarized Total Internal Reflection Fluorescence. Biophys. J. 82: 996-1003.

http://www.cell.com/biophysj/Volume=82

 

Haas, A.S., Pilloud, D.L., Reddy, K.S., Babcock, G.T., Moser, C.C., Blasie, J.K. and Dutton, P.L. Cytochrome c and Cytochrome c Oxidase: Monolayer Assemblies and Catalysis. (2001) J. Phys. Chem. B 105(45): 11351-11362. 

http://pubs.acs.org/Volume=105

 

 

 

Tronin, A. and Blasie, J.K. Variable Acquisition Angle Total Internal Reflection Fluorescence – a New Technique for Orientation Distribution Studies of Ultrathin Films. (2001) Langmuir 17(No. 12): 3696-3703.

http://pubs.acs.org/Volume=17

 

Tronin, A., Strzalka, J., Chen, X., Dutton, P.L., Ocko, B.M. and Blasie, J.K. (2001) Orientational Distributions of the Di-α-Helical Synthetic Peptide ZnPPIX-BBC16 by X-ray Reflectivity and Polarized Epifluorescence. Langmuir 17(10): 3061-3066.

http://pubs.acs.org/Volume=17

 

Zheng, S., Strzalka, J., Ma, C., Opella, S.J., Ocko, B.M. and Blasie, J.K. (2001) Structural Studies of the HIV-1 Accessory Protein Vpu in Langmuir Monolayers: Synchrotron X-ray Reflectivity. Biophys. J. 80(4): 1837-1850.

http://www.cell.com/biophysj/Vol80

 

Kneller, L.R. , Edwards, A.M., Majkrzak, C.F., Berk, N.F., Krueger, S. and Blasie, J.K. (2001) Hydration State of a Single Cytochrome c Monolayer Vectorially-Oriented at a Soft Interface Investigated via Neutron Interferometry. Biophys. J. 80(5): 2248-2261.

http://www.cell.com/biophysj/s?searchTerms=&searchAuthor=&searchVol80 

 

Strzalka, J., Chen, X., Dutton, P.L. and Blasie, J.K. (2001) X-ray Scattering Studies of Maquette Peptide Monolayers II: Interferometry at the Solid/Vapor Interface. Langmuir 17(4): 1193-1199.

http://pubs.acs.org/Volume=17

 

Tronin, A., Strzalka, J., Chen, X., Dutton, P.L. and Blasie, J.K. (2000) Determination of the Porphyrin Orientation Distribution in Langmuir Monolayers by Polarized Epifluorescence. Langmuir 16(25): 9878-9886.

http://pubs.acs.org/Volume=16

 

Strzalka, J., Chen, X., Dutton, P.L., Ocko, B. M. and Blasie, J.K. (2000) X-ray Scattering Studies of Maquette Peptide Monolayers I: Reflectivity and GID at the Air/Water Interface. Langmuir 16(26): 10404-10418.

http://pubs.acs.org/Volume=16

 

A.M. Edwards, K. Zhang, C.E. Nordgren and J.K. Blasie. (2000) Heme Structure & Orientation in Single Monolayers of Cytochrome c on Polar & Nonpolar Soft Surfaces. Biophys. J. 79: 3105-3117.

http://www.cell.com/biophysj/Vol 79

 

Blasie, J.K. and Timmins, P. (1999) Neutron Scattering in Structural Biology & BioMolecular Materials in Neutron Scattering in Materials Research, eds. T. Mason and A. Taylor, MRS Bulletin 24(12): 40-47.

Donald H. Berry

Photo: 
First Name: 
Donald H.
Last Name: 
Berry
Official Title: 
Professor of Chemistry

Inorganic and Organometallic Chemistry

Research Statement

Our research group is concerned with synthesis, structure and mechanism in inorganic and organometallic systems. We are interested in the preparation and study of new organometallic compounds which pose significant questions of structure and bonding, or which are designed to exhibit unusual reactivity in chemical transformations. We are also developing new synthetic routes to inorganic and organometallic polymers. General areas of interest are described below:

 

Contact Information
Office Location: 
554 N
Email: 
berry@sas.upenn.edu
Phone: 
(215) 898-2705
Admin Support: 
Education: 
  • S.B. Massachusetts Institute of Technology (1979)
  • Ph.D. California Institute of Technology (1984)
  • Research Associate, University of Rochester (1985)
  • Alfred P. Sloan Research Fellow (1990)
  • Chair, Chemistry Undergraduate Committee (2000- )
Selected Publications: 

 

"Evidence for Ligand Non-Innocence in a Formally Ruthenium(I) Hydride Complex," Noah L. Wieder, Michelle Gallagher, Patrick J. Carroll, and Donald H. Berry* J. Am. Chem. Soc. 2010, 132, 4107-4109.

 

"Low-Valent Ruthenium Complexes of the Non-innocent 2,6-Bis(imino)pyridine Ligand" Michelle Gallagher, Noah L. Wieder, Vladimir K. Dioumaev, Patrick J. Carroll, and Donald H. Berry* Organometallics, 2010, 29,591-603.

 

D. A. Ruddy, D. H. Berry, and C. Nataro, “Synthesis and characterization of 1-methyl-1-silaindane and 1-methyl-1-germaindane,” J. Organomet. Chem. 2008, 693, 169-172.

 

H. Yoo, P. J. Carroll, and D. H. Berry, “Synthesis and Structure of Ruthenium-Silylene Complexes: Activation of Si-Cl Bonds in N-Heterocyclic Silanes,” J. Amer. Chem. Soc. 2006, 128, 6038-6039. 

 

Y. Huo and D. H. Berry, "Synthesis and Properties of Hybrid Organic-Inorganic Materials Containing Covalently Bonded Luminescent Polygermanes," Chem. Mat., 2005, 17, 157-163.

 

B. Arkles, Y. Pan, G.L. Larson, and D. H. Berry, "Cyclic Azasilanes: Volatile Coupling Agents for Nanotechnology," Silanes and Other Coupling Agents, Vol 3, K.L. Mittal, ed. 2004,.

 

V. K. Dioumaev, L. J. Procopio, P. J. Carroll, and D. H. Berry, "Synthesis and Reactivity of Silyl Ruthenium Complexes: The Importance of Trans Effects in C-H Activation, Si-C Bond Formation, and Dehydrogenative Coupling of Silanes," J. Am. Chem. Soc. 2003, 125, 8043-8058.

 

V. K. Dioumaev, B. R. Yoo, P. J. Carroll, and D. H. Berry "Structure and Reactivity of Bis(Silyl) Dihydride Complexes (PMe3)3Ru(SiR3)2H2: Model Compounds and Real Intermediates in a Dehydrogenative C-Si Bond Forming Reactions," J. Am. Chem. Soc. 2003, 125, 8936-8948.

 

V. K. Dioumaev, P. J. Carroll, and D. H. Berry "Tandem ?-CH Activation / SiH Elimination Reactions: Stabilization of CH Activation Products by beta-Agostic SiH Interactions, " Angew. Chem. Int. Ed. Engl. 2003, 42, 3947-3949.

 

M. Motonaga, H. Nakashima, S. M. Katz, D. H. Berry, T. Imase, S. Kawauchi, M. Fujiki, and J. R. Koe, "The First Optically Active Polygermanes: Preferential Screw Sense Helicity of Enantiopure Chiral-substituted Aryl Polygermanes and Comparison with Analogous Polysilanes," J. Organomet. Chem. 2003, 685, 44-50.

 

K. A. Ezbiansky, D. H. Berry, B. Arkles, and R. J. Composto, Fluoride-Catalyzed Conversion of b-AcetoxyEthyl-Silsesquioxane: a Chloride-Free Pre-cursor for Silica Films", Polym. Prepr., 2001, 42, 101-102.

 

K. A. Ezbiansky, B. Arkles, R. J. Composto, and D. H. Berry, "b-Acetoxyethyl Silsesquioxanes: Chloride-Free Pre-cursors For SiO2 Films Via Staged Hydrolysis," Mater. Res. Soc. Symp. Proc., 2000, 606, 251-256.

 

V. K. Dioumaev, K. Plössl, P. J. Carroll, and D. H. Berry, "Access to Unsaturated Ruthenium Complexes via Phosphine Complexation with Triphenylborane; Synthesis and Structure of a Zwitterionic Arene Complex, (h6-Ph-BPh2H) Ru(PMe3)2(SiMe3).", Organometallics, 2000, 19, 3374-3378.

 

V. K. Dioumaev, K. Plössl, and D. H. Berry, "Formation and Interconversion of Ruthenium-Silene and 16-Electron Ruthenium Silyl Complexes," J. Am. Chem. Soc., 1999, 121, 8391-8392.

 

J. A. Reichl and D. H. Berry "Recent Progress in Transition Metal-Catalyzed Reactions of the Silicon, Germanium, and Tin," Adv. in Organomet. Chem., 1999, 43, 197-265.

 

K. A. Ezbiansky, P. I. Djurovich, M. LaForest, D. J. Sinning, R. Zayes, and D. H. Berry, "Catalytic C-H Bond Functionalization: Synthesis of Aryl-silanes by Dehydrogenative Transfer Coupling of Arenes and Triethylsilane," Organometallics, 1998, 17, 1455-1457.

 

S. M. Katz, J. A. Reichl, and D. H. Berry, "Catalytic Synthesis of Poly-(arylmethylgermanes) by Demethanative Coupling: A Mild Route to s-Conjugated Polymers," J. Am. Chem. Soc., 1998, 120, 9844-9855.

 

L. J. Procopio, P. J. Carroll, and D. H. Berry, "Structure and Reactivity of Cp2Zr(h2-Me2Si=NtBu)(CO): An Unusual Silanimine Carbonyl Complex with Extensive s-p* Back-Bonding," Polyhedron, 1995, 14, 45-55.

Tobias Baumgart

Photo: 
First Name: 
Tobias
Last Name: 
Baumgart
Official Title: 
Professor of Chemistry

Physical and Biological Chemistry

Additional Titles: 
Graduate Chair
Contact Information
Office Location: 
250 Chemistry Bldg.
Email: 
baumgart@sas.upenn.edu
Phone: 
215.573.7539
Fax: 
215.898.6242
Admin Support: 
Education: 

• Postdoctoral associate with Prof. Watt Webb at Cornell University (2001 – 2005)

 

• PhD from Max Planck Institute for Polymer Research and Johannes Gutenberg University of Mainz (2001)

 

• Diploma in Chemistry from the University of Clausthal, Germany (1998)

Research Interests: 

Research in the Baumgart group is largely centered on the physical chemistry of amphiphile membranes with lateral heterogeneity resulting from non-ideal mixing. Our aims include characterization of biologically relevant membranes including lipids and proteins, where we investigate both composition and shape (curvature) heterogeneity. Both of these aspects are thought to be highly relevant to the function of biological membranes. We focus on freely suspended, rather than solid supported membranes, with an emphasis on bilayer membranes, but we also include monolayer systems. We investigate membranes that laterally segregate into co-existing fluid phases, and are particularly interested in quantitatively understanding the phenomenon of line tension at the phase boundary. We also examine molecular details that govern the partitioning of functionally relevant protein constructs between coexisting membrane phases and thereby aim to contribute to enhancing the biophysical understanding of transmembrane signal transduction, particularly in immune cells such as T-cells, B-cells and mast cells. Our research on aspects of membrane shape is directed at understanding how molecules sort in membrane curvature gradients. This curvature sorting likely contributes substantially to intracellular membrane sorting and trafficking. Furthermore we have recently begun to investigate phase coexistence in binary mixtures of amphiphilic di-block copolymers. Finally, we develop methods to pattern cellular signaling ligands, such as antibodies and adhesion molecules, on pattern scales both above and below optical resolution.

Selected Publications: 

31) Heinrich, M., Tian A.,Esposito C., Baumgart T. (2010). Dynamic sorting of lipids and proteins by membrane curvature: a moving phase boundary problem. Proceedings of the National Academy of Sciences. In Print.

30) Johnson, S., Stinson, B., Reminik, J., Go, M., Fang, X., & Baumgart, T. (2010). Temperature dependent phase behavior and protein partitioning in giant plasma membrane vesicles. Biochimica et Biophysica Acta - Biomembranes. In Print.

29) Capraro, B. R., Yoon, Y., Cho, W., Baumgart, T. (2010). Curvature sensing by the epsin N-terminal homology (ENTH) domain measured on cylindrical lipid membrane tethers. Journal of the American Chemical Society, 132 (4), 1200-1201.

28) Levental, I., Byfield, F. J., Choudhourie, P., Madara, J., Gai, F., Baumgart, T., & Janmey P. A. (2009). Cholesterol-dependent phase separation in cell-derived giant plasma membrane vesicles. Biochemical Journal, 424 (2), 163-167.

27) Baker, R. G., Hsu, C. J., Lee, D., Jordan, M. S., Maltzman, J. S., Hammer, D. A., Baumgart, T., & Koretzky, G. A. (2009). The adapter protein SLP-76 mediates “outside-in” integrin signaling and function in T cells. Molecular and Cellular Biology, 29 (20), 5578-5589.

26) Christian, D., Tian, A., Ellenbroek, W., Levental, I., Rajagopal, K., Janmey, P., Liu, A., Baumgart, T., & Discher, D. (2009). Spotted vesicles, striped micelles and Janus assemblies induced by ligand binding. Nature Materials, 8, 843-849. DOI

25) Oh, H., Mohler III, E. R., Tian, A., Baumgart, T., & Diamond, S. L. (2009). Membrane cholesterol is a biomechanical regulator of neutrophil adhesion. Arteriosclerosis, Thrombosis, and Vascular Biology, 29, 1290-1297.

24) Tian, A., Capraro, B. R., Esposito, C., & Baumgart, T. (2009). Bending stiffness depends on curvature of ternary lipid mixture tubular membranes. Biophysical Journal, 97 (6), 1636-1646.

23) Das SL, Jenkins JT, Baumgart T. "Neck geometry and shape transitions in vesicles with co-existing fluid phases: Role of Gaussian curvature stiffness versus spontaneous curvature." Europhysics Letters, 2009, 86, 48003-48008.

22) Tian, A. and Baumgart, T. "Sorting of lipids and proteins in membrane curvature gradients." Biophysical Journal, 2009, 96, 2676-2688.

21) Das S., Tian A., Baumgart T., "Mechanical stability of micropipette aspirated giant vesicles with fluid phase coexistence." Journal of Physical Chemistry, B 2008, 112, 11625-11630.

20) Heinrich M.C., Levental I., Gelman H., Janmey P.A., Baumgart T. "Critical exponents for line tension and dipole density difference from lipid monolayer domain boundary fluctuations." Journal of Physical Chemistry, B 2008, 112, 8063-8068.

Penn Chemistry Alumni Reception at ACS Meeting

Join us at the Philadelphia ACS meeting for an alumni reception!

Ivan Dmochowski honored by McKnight Endowment Fund

Ivan Dmochowski has been named a recipient of a 2012 McKnight Technological Innovations in Neuroscience Award along with his colleague James Eberwine (Perelman School of Medicine). The McKnight Endowment Fund for Neuroscience supports research projects that develop and apply innovative technologies for studying the brain and its diseases.

James Eberwine, PhD, Professor of Pharmacology, and Ivan J. Dmochowski, Associate Professor of Chemistry, University of Pennsylvania, "TIVA-tag Enables True Neuronal Systems Genomics"

Madeleine Joullié Oral History Featured by CHF

The Chemical Heritage Foundation, located in Philadelphia, has hosted more than 400 oral histories from the biggest names in the field of chemistry. Madeleine Joullié's oral history is highlighted in the July issue of First Person. Click the link to read it.

Jeffrey Winkler's Research Featured

Prof. Jeffrey Winkler's collaborative research effort with Prof. Ravi K. Amaravadi and colleagues in the Perelman School of Medicine and the Abramson Cancer Center is featured in an early edition of PNAS. The research focuses on development of a potent new drug that clogs up the recycling machinery of tumor cells.

 

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