Myostatin is a member of the TGF- beta superfamily that is essential for proper regulation of skeletal muscle mass in a number of species ranging from fish to s. Myostatin is a secreted Protein that negatively regulates skeletal muscle mass determining both muscle fiber number and size. Inhibition of myostatin can increase muscle mass in a number of animal models of disease, including muscular dystrophy. Recombinant Myostatin is a non-glycosylated homodimer, containing two 109 amino acid chains, with a total molecular weight of 24.8 kDa.