Occurrence of an Affinity Site apart from the Active Site on the Raw-Starch-Digesting but Non-Raw-Starch-Adsorbable Bacillus subtilis 65 alpha-Amylase.

alpha-Cyclodextrin specifically inhibited raw starch digestion by Bacillus subtilis 65 alpha-amylase. The raw starch digestibility and alpha-cyclodextrin-Sepharose 6B adsorbability of this alpha-amylase were simultaneously lost when the specific domain corresponding to the affinity site essential for raw starch digestion was deleted by proteolysis. Occurrence of the affinity site on raw-starch-digesting enzymes was proven also with bacterial amylase.