Multiple forms of β-galactosidase from mango (Mangifera indica L Alphonso) fruit pulp

Prasanna, V. and Prabha, T. N. and Tharanathan, R. N. (2005) Multiple forms of β-galactosidase from mango (Mangifera indica L Alphonso) fruit pulp. Journal of the Science of Food and Agriculture, 85. pp. 797-803.

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Abstract

Mango (Mangifera indica L cv Alphonso) was found to contain three isoforms (I, II and III) of β-galactosidase which, upon purification on Sephadex G-200, had relative abundances of 44, 38 and 18%, respectively. The total specific activity increased from 20 to 727 µmol l−1 upon purification, representing a ∼36-fold increase with a recovery of 0.28UU−1. The optimal pH for activity and stability were in the ranges 3.6–4.3 and 4–6.2, respectively. The optimal temperature for β-galactosidase activity was between 42 and 47 ◦C with Tm in the range 45–51 ◦C. The Km for pNP-β-galactopyranoside was 0.98, 1.11 and 0.95mM, and Vmax was 0.56, 0.53 and 0.35 µmol pNP min−1, respectively for isoforms I, II and III. Hg2+ caused strong inhibition, whereas galacturonic acid, galactose, xylose, fucose and mannose slightly inhibited the activity of β-galactosidase isoforms. The apparent molecular weights by GPC were 78, 58 and 91 kDa for isoforms I, II and III, respectively. The ability of these isoforms to degrade the endogenous substrate (arabinogalactan) possibly suggests a role in pectin dissolution during tissue softening/fruit ripening.

Item Type:	Article
Uncontrolled Keywords:	mango; β-galactosidase; pectin; arabinogalactan; ripening
Subjects:	600 Technology > 08 Food technology > 24 Fruits > 06 Mango 600 Technology > 08 Food technology > 14 Physical properties 500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 28 Polysaccharide Chemistry
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	26 Jun 2008 05:36
Last Modified:	25 Apr 2012 09:33
URI:	http://ir.cftri.res.in/id/eprint/1771

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