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Pharmacy Faculty Articles and Research

2012

Calmodulin

Articles 1 - 2 of 2

Full-Text Articles in Medicine and Health Sciences

Identification Of The Functional Binding Pocket For Compounds Targeting Small-Conductance Ca2+-Activated Potassium Channels, Miao Zhang, John M. Pascal, Marcel Schumann, Roger S. Armen, Ji-Fang Zhang Aug 2012

Identification Of The Functional Binding Pocket For Compounds Targeting Small-Conductance Ca2+-Activated Potassium Channels, Miao Zhang, John M. Pascal, Marcel Schumann, Roger S. Armen, Ji-Fang Zhang

Pharmacy Faculty Articles and Research

Small- and intermediate-conductance Ca2+-activated potassium channels, activated by Ca2+-bound calmodulin, play an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels. However, these compounds often suffer from low potency and lack of selectivity, hindering their potentials for clinical use. A key contributing factor is the lack of knowledge of the binding site(s) for these compounds. Here we demonstrate by X-ray crystallography that the binding pocket for the compounds of the 1-EBIO class is located at the calmodulin-channel interface. We …


Structural Basis For Calmodulin As A Dynamic Calcium Sensor, Miao Zhang, Cameron Abrams, Liping Wang, Anthony Gizzi, Liping He, Ruihe Lin, Yuan Chen, Patrick J. Loll, John M. Pascal, Ji-Fang Zhang May 2012

Structural Basis For Calmodulin As A Dynamic Calcium Sensor, Miao Zhang, Cameron Abrams, Liping Wang, Anthony Gizzi, Liping He, Ruihe Lin, Yuan Chen, Patrick J. Loll, John M. Pascal, Ji-Fang Zhang

Pharmacy Faculty Articles and Research

Calmodulin is a prototypical and versatile Ca2+ sensor with EF-hands as its high-affinity Ca2+ binding domains. Calmodulin is present in all eukaryotic cells, mediating Ca2+-dependent signaling. Upon binding Ca2+, calmodulin changes its conformation to form complexes with a diverse array of target proteins. Despite a wealth of knowledge on calmodulin, little is known on how target proteins regulate calmodulin’s ability to bind Ca2+. Here, we take advantage of two splice variants of SK2 channels, which are activated by Ca2+-bound calmodulin, but show different sensitivity to Ca2+ for their activation. Protein crystal structures and other experiments show that depending on which …