Stephanie Tristram-Nagle

Research Professor, Physics

Education

Ph.D., University of California, Berkeley

Research

My research interests are in lipid membrane structure and thermodynamics. Our Biophysics laboratory explores the structure of biological phospholipids, lipid/peptide and lipid/cholesterol mixtures using oriented samples on substrates and unoriented multilamellar or large unilamellar vesicles using X-ray diffraction with a Rigaku rotating anode and CCD detector here at CMU, and with synchrotron radiation at the Cornell High Energy Synchrotron Source.  We also use differential scanning calorimetry to measure specific heat changes during phase transitions of aqueous dispersions of phospholipids in the form of MLVs. The third technique which yields structural information about the lipid volume as a function of temperature is density equilibration, using D₂O-H₂O mixtures.

Selected Publications

• Kelsey M. Hallinen, Stephanie Tristram-Nagle, John F. Nagle, Volumetric stability of lipid bilayers, Physical Chemistry Chemical Physics 14, 15452 (2012)
• Jianjun Pan, Frederick A. Heberle, Stephanie Tristram-Nagle, Michelle Szymanski, Mary Koepfinger, John Katsaras, Norbert Kučerka, Molecular structures of fluid phase phosphatidylglycerol bilayers as determined by small angle neutron and X-ray scattering, Biochimica et Biophysica Acta (BBA) - Biomembranes 1818, 2135 (2012)
• Mohit Raghunathan, Yuriy Zubovski, Richard M. Venable, Richard W. Pastor, John F. Nagle, Stephanie Tristram-Nagle, Structure and Elasticity of Lipid Membranes with Genistein and Daidzein Bioflavinoids Using X-ray Scattering and MD Simulations, The Journal of Physical Chemistry B 116, 3918 (2012)
• Anthony R. Braun, Eva Sevcsik, Pamela Chin, Elizabeth Rhoades, Stephanie Tristram-Nagle, Jonathan N. Sachs, α-Synuclein Induces Both Positive Mean Curvature and Negative Gaussian Curvature in Membranes, Journal of the American Chemical Society 134, 2613 (2012)
• P Shchelokovskyy, S Tristram-Nagle, R Dimova, Effect of the HIV-1 fusion peptide on the mechanical properties and leaflet coupling of lipid bilayers, New Journal of Physics 13, 025004 (2011)
• Pradeep Uppamoochikkal, Stephanie Tristram-Nagle, John F. Nagle, Orientation of Tie-Lines in the Phase Diagram of DOPC/DPPC/Cholesterol Model Biomembranes, Langmuir 26, 17363 (2010)
• Stephanie Tristram-Nagle, Rob Chan, Edgar Kooijman, Pradeep Uppamoochikkal, Wei Qiang, David P. Weliky, John F. Nagle, HIV Fusion Peptide Penetrates, Disorders, and Softens T-Cell Membrane Mimics, Journal of Molecular Biology 402, 139 (2010)
• Stephanie Tristram-Nagle, Dong Joo Kim, Nadia Akhunzada, Norbert Kučerka, John C. Mathai, John Katsaras, Mark Zeidel, John F. Nagle, Structure and water permeability of fully hydrated diphytanoylPC, Chemistry and Physics of Lipids 163, 630 (2010)
• Jianjun Pan, Stephanie Tristram-Nagle, John Nagle, Effect of cholesterol on structural and mechanical properties of membranes depends on lipid chain saturation, Physical Review E 80, 021931 (2009)
• S. Deren Guler, D. Dipon Ghosh, Jianjun Pan, John C. Mathai, Mark L. Zeidel, John F. Nagle, Stephanie Tristram-Nagle, Effects of ether vs. ester linkage on lipid bilayer structure and water permeability, Chemistry and Physics of Lipids 160, 33 (2009)
• Jianjun Pan, Thalia Mills, Stephanie Tristram-Nagle, John Nagle, Cholesterol Perturbs Lipid Bilayers Nonuniversally, Physical Review Letters 100, 198103 (2008)
• A. Greenwood, J. Pan, T. Mills, J. Nagle, R. Epand, S. Tristram-Nagle, CRAC motif peptide of the HIV-1 gp41 protein thins SOPC membranes and interacts with cholesterol, Biochimica et Biophysica Acta (BBA) - Biomembranes 1778, 1120 (2008)
• Thalia T. Mills, Gilman E.S. Toombes, Stephanie Tristram-Nagle, Detlef-M. Smilgies, Gerald W. Feigenson, John F. Nagle, Order Parameters and Areas in Fluid-Phase Oriented Lipid Membranes Using Wide Angle X-Ray Scattering, Biophysical Journal 95, 669 (2008)