Isolation of an amylase inhibitor from Setaria italica grains by affinity chromatography on Blue-Sepharose and its characterization

• Published in: Journal of agricultural and food chemistry 1985-01, Vol.33 (4), p.646-650
• Main Authors: Nagaraj, Ramanakoppa H, Pattabiraman, Thillaisthanam M
• Format: Article
• Language: English
• Subjects: affinity chromatography; Agronomy. Soil science and plant productions; amilasas; amylase; amylase inhibitor; amylases; Applied sciences; Biological and medical sciences; Cereal and baking product industries; chromatographie; chromatography; cromatografia; enzyme inhibitors; Exact sciences and technology; Food industries; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Generalities. Production, biomass, yield. Quality; grain; inhibidores de enzimas; inhibiteur d' enzyme; Other techniques and industries; Setaria italica
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf00064a019

An alpha -amylase inhibitor from Setaria italica grains was purified 150-fold by chromatography on Blue-Sepharose after neutralization of the acid extract and ammonium sulfate fractionation. The inhibitor was found to be homogenous by polyacrylamide gel electrophoresis and gel chromatography on BioGel P-30. The molecular weight was found to be 24 K. SDS-PAGE showed that it is made up of two dissimilar polypeptides. Affinity chromatography on immobilized porcine pancreatic amylase and analysis showed that both the polypeptides are essential for the action of the inhibitor. The setaria inhibitor acted on human salivary amylase, human pancreatic amylase, and porcine pancreatic amylase but had no action on B. subtilis and A. oryzae amylases. It was labile to heat and to extreme acidic and alkaline conditions. Pronase, pepsin, trypsin, and alpha -chymotrypsin inactivated the inhibitor. Amino groups and guanido groups were found to be essential for its action.