Fig. 3. Design of decoy peptides. The "L-shaped" structure of monomeric PLB is composed of a cytoplasmic helix, a connecting short loop, and a transmembrane helix. Blue box, ψPLB-SE was derived from the nine amino acids that compose the connecting loop. In the decoy peptide, the serine residue was replaced with a glutamine to mimic the peptide in its phosphorylated state (shown in green). The peptide was conjugated via a disulfide bond at the amino-termini to the cell penetrating peptide TAT (YG-RKKRRQRRR) to facilitate uptake of the peptide into cells.