Midkine, a heparin-binding growth factor, contains 121 amino acid residues with 5 disulfide bonds. It promotes the growth, survival, and migration of various cells, and plays roles in neurogenesis and epithelial mesenchymal interactions during organogenesis. The C-terminal portion contains the heparin-binding domain and the antigenicity and neurite-promoting sequences. Both the C- and N-terminals are necessary for the moleculeμs neurotrophic effects.
