The primary structure and elastinolytic activity of medullasin (a serine protease of bone marrow)

The amino acid sequence around the carboxyl terminal of medullasin was determined by digesting the protease with carboxypeptidase Y and measuring the rate of release of amino acids from the carboxyl terminal. By considering the structure of the protease's cDNA, we concluded that His-238 is the C-terminal residue of medullasin. Therefore, medullasin is composed of 238 amino acid residues with Ile as the amino terminal and His as the carboxyl terminal. Medullasin is essentially devoid of elastinolytic activity, because it failed to digest orcein-elastin.