Inhibitory Effects of the Proteinaceous a-Amylase Inhibitor Haim on Animal α-Amylaset

Susceptibility of animal α-amylases to a proteinaceous α-amylase inhibitor, Haim, vary with species of the animal and among organs of the same animal. Haim strongly inhibits, α-amylases from vertebrates, and weakly inhibits those from Mollusca, Annelida, and Arthropoda. The results suggest that susceptibility of animal α-amylases to Haim may correlate well with the classification of the animal. Haim had greater specificity for human salivary amylase than for human pancreatic amylase, and greater specificity for rat pancreatic amylase than for rat salivary amylase.Maximum inhibition of hog pancreatic amylase by Haim occurred after preincubation of the enzyme and its inhibitor at 37°C for 3 min. The time required to reach maximum inhibition was shorter for Haim than for inhibitors from kidney bean and wheat.Complex formation between Haim and hog pancreatic α-amylase was seen by UV difference spectroscopy. That the molar complex was 1:1 was also shown by the same method and by an inhibition curve.