MPSD TFA (MARCKS-ED TFA) is the TFA salt form of MPSD. MPSD TFA is a 25-amino acid peptide based on the effector domain sequence of the intracellular membrane protein myristoylated alanine-rich C-kinase substrate ( MARCKS ). MPSD TFA can sense membrane curvature and recognize phosphatidylserine. MPSD TFA can be utilized as biological probe to study membrane shape and lipid composition.