We are also interested in the mechanism of gating and selectivity in ion channels. Research in our lab is focused on the structure and function of phospholamban, a 52-residue ion channel protein found in cardiac muscle cells that regulates calcium levels across the sarcoplasmic reticulum membrane.

Phospholamban is essential in b-adrenergic response in the heart. During muscle contraction, phospholamban binds to the Ca2+ pump and prevents Ca2+ from being pumped back into the SR. During muscle relaxation, phospholamban is phosphorylated by Protein Kinase A at Ser16 and Thr17 which removes the inhibition and restores low calcium levels in the cytoplasm. Though the 52-residue peptide is most inhibitory as a monomer, phospholamban also associates into pentamers that have been shown to be selective for Ca2+ ions.

The structure of phospholamban is central to its function. We are using various biochemical and biophysical methods to investigate the structure and function of this peptide and to understand its mechanism. We are able to determine its global secondary structure by CD and FTIR spectroscopy, and full three dimensional structure by solid state NMR