Three alpha-amylases from malted finger millet (Ragi, Eleusine coracana,Indaf-15)—purification and partial characterization

Nirmala, M. and Muralikrishna, G. (2003) Three alpha-amylases from malted finger millet (Ragi, Eleusine coracana,Indaf-15)—purification and partial characterization. Phytochemistry, 62. pp. 21-30.

PDF Phytochemistry_62_(2003)_21-30.pdf Restricted to Registered users only Download (237kB)

Abstract

Three alpha-amylases (E.C. 3.2.1.1) were purified to apparent homogeneity from 72 h finger millet malt by three step purification via fractional acetone precipitation, DEAE-Sephacel ion exchange and Sephacryl S-200 gel permeation chromatographies with a recovery of 6.5, 2.9, 9.6% and fold purification of 26, 17 and 31, respectively. a-Nature of these amylases was identified by their ability to rapidly reduce the viscosity of starch solution and also in liberating oligosaccharides of higher D.P. and were accordingly designated as amylases a-1(b), a-2 and a-3, respectively.These amylases, having a molecular weight of 45�2 kDa were found to be monomeric.The pH and temperature optima of these a-amylases were found to be in the range of 5.0–5.5 and 45–50 oC, respectively. Km values of these amylases for various cereal starches varied between 0.59 and 1.43%. Carbodiimide (50 mM) and metal ions such as Al3+, Fe2+, and Hg2+ (5 mM) have completely inhibited these enzymes at 45oC.Amino acid analysis of these enzymes indicated high amounts of glycine which is an unusual feature of these enzymes.

Item Type:	Article
Uncontrolled Keywords:	alpha-Amylases; Finger millet; Ragi; Eleusine coracana; Purification; Partial characterization
Subjects:	600 Technology > 08 Food technology > 21 Cereals > 05 Ragi (Finger Millet) 500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 16 Enzyme Chemistry
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	24 Sep 2007 11:29
Last Modified:	28 Dec 2011 09:30
URI:	http://ir.cftri.res.in/id/eprint/1429

Actions (login required)

View Item