Ion channel are membrane embedded enzymes that catalyze the selective flow of ions across biological membranes. In order to do this, an ion channel must transition along well defined kinetic states: Closed (C), Open (O) and Open-Inactivated (OI), which are presumably associated to characteristic structural changes. Our laboratory is committed to understand how structural changes determine a given ion channel kinetic state. Our approach involves an extensive electrophysiological characterization of the recombinant protein reconstituted in giant liposomes, which is highly advantageous since allows full access to the intracellular and extracellular milieu on the same sample.

Luis G. Cuello Laboratory

Center for Membrane Protein Research


pH jump experiment of KcsA containing liposomes.

    In our laboratory the structural dynamics of ion channels in full action are detected by using Side Directed Spin Label (SDSL) and Electron Paramagnetic Resonance Spectroscopy (EPR). This approach allow us to investigate the structural changes associated with the activation and inactivation gating of ion channels.

Spin label sampling structural dynamics in a protein

CW-EPR spectral changes track KcsA conformational changes associated to the activation process

EPR environmental parameters mapped onto KcsA structure depicted the structural changes associated to activation gating

   An atomic resolution characterization of the gating cycle of an ion channel is starting to emerge by trapping these enzymes in different structural intermediates along their kinetic cycle and solving their structure by X-ray crystallography. Our laboratory is fully committed in the elucidation of the X-Ray structures of ion channels “trapped” in different structural intermediates.

X-ray structure of KcsA trapped  in the open inactivated state

   A linear interpolation from KcsA closed to open state highlighting in atomic details molecular events underlying ion channel gating process (Cuello et al. unpublished data)

Luis G. Cuello PhD

Associate Professor

Ph. (806) 7432525

Lab. (806) 7431140

Elucidation of the structure -function relationship of ion channels by Functional, Spectroscopic and Crystallographic approaches

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