Physics Colloquium: Jan Behrends

The Syracuse University Physics Department is pleased to welcome Dr. Jan Behrends, Professor of Physiology at the University of Freiburg, Germany.

Dr. Behrends studied medicine at the University of Munich where he obtained his doctorate (M.D., 1993) with an experimental thesis on “Mechanisms of Calcium-Dependent Regulation of Neuronal Excitability.” After postdoctoral fellowships at the Institut Pasteur in Paris (INSERM poste vert) and the Max-Planck-Institute for Psychiatry in Munich-Martinsried (DFG-fellowship), he became a Research Associate (1995) and Assistant Professor (1997) at the Department of Physiology of the University of Munich and obtained the Habilitation and venia legendi for Physiology with a thesis on “Elemental Events and Functional Principles of Inhibitory Neurotransmission” in 2001. In 2002, he co-founded Nanion Technologies GmbH, Munich, on the basis of the first demonstration of the chip-based planar version of the patch clamp technique. In 2014, based on the microelectrode cavity array (MECA) technology for autiomated and parallel planar bilayer recordings, he co-founded Ionera Technologies GmbH, Freiburg.

He is a founding associate member of the Center for Nanoscience of the University of Munich, vice-spokesman of a nanodiagBW, a large, federally founded cluster project for nanopore technology, as well as spokesman of nEOdiag, a multidisciplinary consortium on nanopore sensing funded by the Carl-Zeiss-Foundation. He is also Chairman of the Advisory Boards of Nanion Technologies GmbH and Ionera Technologies GmbH. His research has covered large areas of cellular and membrane electrophysiology, including mechanisms of synaptic transmission and is now focused on the development of novel experimental tools for electrophysiology, biophysics and nanoscience, including automated high-throughput patch-clamp, lipid bilayer recording systems and, most recently, nanopore-based analytics.

“Probing the shape of macromolecules with ions: from polymer sizing to sequencing”

Abstract:

When a macromolecule enters a narrow ion-conducting path through an insulator, such as a protein pore of channel in a membrane or a nanoscopic aperture in a crystalline substrate, any current driven by a voltage through this path is reduced. The sensitivity of the residual current to the nature of the “blocker” is such that when e.g. single stranded DNA is driven through a pore in a linear, controlled fashion, so that few monomers determine the residual conductivity, the resulting  current pattern can be used to deduce the sequence of nucleotides. Alternatively, by stochastically entrapping an entire macromolecule in a pore, the residual current -now jointly determined by all monomers- can be used to discriminate between different sizes and even shapes of analytes with surprising sensitivity. A method will be shown to use this principle to discriminate between positional isomers of peptides resulting from posttranslational modification of human histone proteins. In addition, an approach will be introduced to use whole molecule nanopore trapping for peptide sequence recognition by sequential cleavage of peptide bonds, opening an avenue towards direct protein sequencing by nanopore.