We study the relationship between the structure and the physiological function of ion channel proteins.

This is a picture of the first potassium channel to have its crystal structure solved (Doyle et al., Science 280:69 1998).  It is a homotetramer: 4 identical subunits (coded with the same set colors for different chains within the subunit) forming the functional channel.  When all four dark green strands are toward you, you are looking into the ion channel pore from the external surface of the pore.  In cross-section the narrow pore region is seen- coded by light green.  As many as four or five potassium ions can simultaneously bind to the pore in this protein.  One important question is how does this structure allow high ion throughput in the face of high ion selectivity and tight (even if only transient) binding.

Research Overview

Ion channel proteins control the movement of ions across the membranes of essentially all cells.  The voltage-gated ion channel proteins are responsible for the electrical activity of nerves, skeletal muscle, and cardiac muscle.  Calcium sensitive ion channels control, for example, the fluid secretion properties of epithelial cells in the salivary glands, pancreas, and kidneys.  We are interested in determining the molecular identity of some of these channels (their genetic code) and how their different components gives the channels their unique properties and how these properties are used in physiological systems.  "Click" below for details on specific projects:

• K Channel Selectivity and Permeation

• Fluid Secretion in the Parotid Gland