The Department of Physics in the J. William Fulbright College of Arts and Sciences presents its Physics Colloquium, titled "A new frontier in single-molecule detection: polypeptides in nanopore sensors" by David P. Hoogerheide of the National Institute of Standards and Technology. The lecture will be from 4-5 p.m. Friday, March 9, in PHYS 133. Refreshments will begin at 3:30 p.m. in PHYS 134.

The talk highlights the motion of charged biomolecules across membranes has significant consequences for technology, for biology and medicine, and for the biophysics and physical chemistry of biomolecule/membrane association. Technologically, DNA motion through nanopores is the central mechanism for nanopore-based sequencing technologies.

From a medical perspective, movement of native proteins across membranes is critical for normal cellular functioning, while therapeutic peptides must be designed to target and penetrate diseased cells. And from a more fundamental view, a thin pore is the simplest possible way to confine a single polymer. The next frontier in nanopore-based detection is the study of heterogeneously charged molecules such as block copolymers or polypeptides.

In this talk, Hoogerheide will demonstrate how the complexity of a heterogeneously charged polypeptide can be leveraged experimentally to observe translocation success at the single-molecule level. The experimental results will be matched to simple stochastic dynamical models. Along the way, we will discover new approaches to studying polypeptides with nanopores, new tools for predictive modeling of experimental observations, and a new assay for studying the binding of polypeptides to lipid membranes on the single-molecule level.