Abstract
Medullasin is a neutral proteinase first purified by Aoki from the mast cells of bone marrow (Aoki (1978) J. Biol. Chem. 253, 2026-2032) . It causes an artificial inflammation when injected into the skin of experimental animals, thus considered to be an agent responsible for the occurrence of pathogenic inflammation. The proteolytic activity of medullasin was effectively inhibited by stoichiometric amounts of a serum proteinase inhibitor α2-macroglobulin and its egg white homolog, ovomacroglobulin.
Competitive inhibition of medullasin by α-1-proteinase inhibitor and α2-macroglobulin was studied under a simulated in vivo condition and it was shown that even in the presence of 30 fold molar excess of α-1-proteinase inhibitor 30-40% of medullasin was bound to α2-macroglobulin, indicating that the latter inhibitor can be an effective modulator of inflammation in vivo.
Ovomacroglobulin was also proved to be an effective inhibitor under similar conditions.
