ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (11), pp. 001-005, November, 2018. © International Scholars Journals
Full Length Research Paper
Alpha-amylase inhibitor of amadumbe (Colocasia esculenta): Isolation, purification and selectivity toward - amylases from various sources
R. McEwan1*, R. P. Madivha1, T. Djarova1, O. A. Oyedeji2 and A. R. Opoku1
1Department of Biochemistry and Microbiology, University of Zululand, P/B X1001, KwaDlangezwa 3886, South Africa.
2Department of Chemistry, University of Zululand, P/B X1001 KwaDlangezwa 3886, South Africa.
Accepted 25 June, 2018
Abstract
Two proteins (A-1 and B-2) with a-amylase inhibitor activity were extracted and partially purified from Colocasia esculenta tubers through 80% ammonium sulphate fractionation, ion-exchange chromatography on DEAE -Sephacel and gel-chromatography on Sephadex G-100. The molecular weight of A-1 and B-2 were estimated to be about 17000 and 19000 daltons, respectively. The inhibitors inactivated a-amylases of animal origin, but had no effect on fungal amylase. Inhibitor A-1 also exhibited activity towards plant amylases, while inhibitor B-2 has no activity on plant amylases. Inhibitor A-1 was the most active against human salivary amylase at pH 6. Inhibitor A-1 was completely destroyed at temperatures above 50°C; while inhibitor B-2 was stable up to 70°C.
Key words: a-amylase inhibitor, amadumbe, Colocasia esculenta, diabetes, obesity.