Relationship of disulfide bonds to the maintenance of the active secondary structure of alfalfa (Medicago sativa ) leaves protease inhibitor

The polypeptide inhibitor of the alfalfa leaves serine protease contains four disulfide bridges and a high (40-50%) ?-helix secondary structure content for an Mr of 6300. The progressive reduction of the four disulfide bridges results in a progressive loss of both the ?-helix secondary structure content and the biological activity. © 1986 American Chemical Society.