Physiology and Biophysics Faculty

Research Interests

We apply engineering as usual to biological ion channels to determine which physics are used by the channels to achieve crucial biological functions. For instance, how do channels select among physiological ions, and how do they conduct the selected ions through cell membranes? How do channels regulate their ionic conduction in response to the cell's membrane potential? These capabilities underly bioelectricity.

Much of our current work is computational, with some experimental extensions to test the theories we develop. We collaborate closely with many scientists in diverse disciplines in the U.S and abroad. These include researchers in physical chemistry, computational electronics, and applied mathematics, who work with us to apply advanced methods of their fields to our biological problem. Our results are published in physical as well as physiological journals (see below).

Like engineers, we try to focus on elements that are crucial for a function and to elaborate their physical interactions to the level of detail needed to understand and predict the function. This reductionist approach is illustrated in a our view of the `selectivity filter' of an L-type Ca channel (see figure). Here, some crucial charged atoms of the channel lining are represented explicitly (red spheres). Their interactions with permeating ions (green and yellow spheres) are computed explicitly. The rest of the channel macromolecule is described at a much coarser scale of resolution. We sample the interactions of interest using direct (Monte-Carlo) simulation of this charged particle system, and we seek to develop statistical-mechanical theory describing the system's average behavior (such as the average number of Ca ions attracted into the selectivity filter from baths of varied ionic compositions). Equilibrium theory that we work out for this filter is included into a drift/diffusion description of ion flow that occurs when ions experience a driving force across the channel.

From Right to Left:
Alex Peyser, Umbrella Tree, Wolfgang Nonner

• Google Scholar Citations
• PubMed Citations

Selected Publications

1. Nonner W, Peyser A, Gillespie D, Eisenberg B (2004) Relating microscopic charge movement to macroscopic currents: the Ramo-Shockley theorem applied to ion channels. Biophys J. 87(6):3716-22.
2. Miedema H, Meter-Arkema A, Wierenga J, Tang J, Eisenberg B, Nonner W, Hektor H, Gillespie D, Meijberg W (2004) Permeation properties of an engineered bacterial OmpF porin containing the EEEE-locus of Ca2+ channels. Biophys J. 87(5):3137-47.
3. Boda D, Gillespie D, Nonner W, Henderson D, Eisenberg B (2004) Computing induced charges in inhomogeneous dielectric media: application in a Monte Carlo simulation of complex ionic systems. Phys Rev E Stat Nonlin Soft Matter Phys. 69(4 Pt 2):046702.
4. Gardner CL, Nonner W, and Eisenberg B (2004). Electrodiffusion model simulation in ionic channels: 1D simulations. J. Computational Electronics 3(1):25-31.
5. Gillespie D, Nonner W, and Eisenberg B (2002). Coupling Poisson-Nernst-Planck and density functional theory to calculate ion flux. J. Physics.: Condensed Matter 14:12129-12145.
6. Nonner W, Catacuzzeno L, Eisenberg B (2000) Binding and selectivity in L-type calcium channels: a mean spherical approximation. Biophys J. 79(4):1976-92. 
7. Nonner W. and Eisenberg B (1998). Ion permeation and glutamate residues linked by Poisson-Nernst-Planck theory in L-type calcium channels. Biophys. J. 75:1287-1305.
8. Conti F, Hille B, Neumcke B, Nonner W, and Staempfli R (1976). Measurement of the conductance of the sodium channel from current fluctuations at the node of Ranvier. J. Physiol. 262:699-727.
9. Nonner W, Rojas E, and Staempfli R (1975). Gating currents in the node of Ranvier: voltage and time dependence. Phil. Trans. R. Soc. Lond. B. 270:483-492.

Curriculum Vitae

• 1968 M.D. Medical Faculty, University of the Saarland, Germany
• 1968-1971 Research Associate, Physiology, University of the Saarland
• 1972-1978 Assistant Professor, Physiology, University of the Saarland
• 1978-1980 Research Associate Professor, Physiology and Biophysics, University of Washington, Seattle
• 1981-1991 Associate Professor, Dept. of Physiology and Biophysics, University of Miami School of Medicine
• 1991-present Professor, Dept. of Physiology and Biophysics, University of Miami School of Medicine