Complex Formation of Alkaline Protease Inhibitor (AP-I) with Subtilisin BPN' and Its Properties

抄録

EI complex formation of AP-I, existing as dimer, with subtilisin BPN' was investigated in detail.
By changing the E/I₂ ratio in the reaction mixture, two types of EI complex were recognized; E₂I₂ complex which was composed of two moles of subtilisin BPN' and one mole (two subunits) of AP-I, and EI₂ complex which was composed of one mole of the enzyme and one mole of AP-I. Their existence was demonstrated by gel filtration, inhibitory equivalent, disc electrophoresis and isoleucine content in the complexes.
The former complex is thought to be a final and stable complex, and the latter to be an intermediate or transient type of complex.