Characterization of α-amylase inhibitor from Palo Fierro seeds

Alpha amylase inhibitor from Palo Fierro seeds (αAI-PF) was purified using affinity chromatography on a fetuin-fractogel column followed by anionic exchange chromatography. αAI-PF has a molecular mass of 77 kDa with two subunits (15.8 and 17.4 kDa), it is nonglycosylated and has pI of 4.7. αAI-PF inhibited porcine pancreatic α-amylase (PPA) (1,4-α-d-glucan glucanohydrolase; EC 3.2.1.1), but was almost devoid of inhibitory activity on α-amylase extracts from Zabrotes subfasciatus (ZSA). Analysis of αAI-PF peptides showed a high homology to αAI-1 from Phaseolus vulgaris that also inhibits PPA.