Research Interests:

Biophysics of excitation: Structure Function in Voltage Dependent Ionic Channels.
In voltage dependent channels, the electrical expression of their function is the ionic current which can be studied at the macroscopic level (the ionic current) and at the microscopic level (the single channel recording). But in addition to the ionic current, in these molecules the rearrangement of internal dipoles and charged groups under the influence of the external electric field produce gating currents. These currents are a direct expression of molecular rearrangements relevant to the operation (or gating) of the channel molecule.
With the advent of molecular cloning techniques, we have been able to carry out these studies with a detail not possible before by recording gating currents of cloned Shaker K+ channels and describing their electrical properties with high resolution. Thus, we can modify the molecule to probe the role of specific amino acids in the voltage dependence and charge movement of the channel.
The main interest in the lab is the search for the molecular basis of the voltage sensor operation. This is being approached with physical techniques such as temperature effects and complex capacitance measurements in the frequency domain combined with mutations of the channel molecule and assessed by gating currents, macroscopic currents and single channel recordings. The correlation with structural changes are being monitored with optical techniques using fluorescence changes and fluorescence resonance energy transfer from probes attached to strategic sites in the channel molecule.