Computational Modeling of Protein Kinase A and Comparison with Nuclear Magnetic Resonance Data

Abstract

Protein phosphorylation is fundamental in the modulation of myocardial contractility. Sarcoendoplasmic reticulum Ca2+ ATPase(SERCA) removes cytosolic Ca2+ to initiate relaxation, but the regulatory protein, phospholamban(PLN), decreases SERCA’s affinity for free Ca2+. Phosphorylation of PLN by Protein Kinase A (PKA) induces a relief of inhibition on SERCA and augments the rate of SERCA Ca2+ uptake. Here, we studied the interaction between PKA and PLN by nuclear magnetic resonance (NMR), computational docking and molecular dynamics (MD) simulations. Comparative simulations of PKA apo, binary and ternary states were performed, which provided molecular details to understand the mechanism of PKA substrate recognition.