Objectives

The ultimate goal of this research is to provide single molecule equivalents to the existing battery of gel electrophoretic methods. These nanopore methods would determine the number and type of proteins in samples the size of a single cell and provide real-time monitoring of the assembly of multi-protein structures.

The short-term objectives are to:

1. use nanopores to distinguish proteins based on coarse-grain differences (10-30 amino acid stretches) in their primary sequence,
2. evaluate competing models of the translocation physics,
3. develop electrochemical impedance spectroscopy as a method to determine nanopore shape and size and evaluate the interactions between protein and the nanopore,
4. identify the nanopore geometries that are most suitable for protein identification,
5. optimize the physical and chemical treatment of the nanopore surface for measurement of proteins, and
6. develop new nanopore measurements that do not disrupt protein assemblies.

Background

The use of the resistive pulse method to determine the size of microscopic particles in a small pore dates back to Coulter in the 1950's. Recently nanofabrication of single pores with nanometer dimensions has enabled similar studies of single molecules. The Talaga group has been collaborating with the Li group at U. Arkansas to make measurements on proteins under amyloidogenic conditions, with the goal of measuring the shape and size distribution of aggregation intermediates.