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Trichoderma reesei alpha-galactosidase activity on locust bean and guar galactomannans

Author:
Kim, S.M., Penner, M.H.
Source:
Journal of food biochemistry 2004 v.28 no.4 pp. 293-303
ISSN:
0145-8884
Subject:
Hypocrea jecorina, guar gum, locust bean gum, galactomannans, biodegradation, microbial activity, alpha-galactosidase, fungal proteins, enzyme activity, enzymatic hydrolysis, polymerization, hydrolysates, galactose, mannose, glycosides, enzyme kinetics, functional properties, gels
Abstract:
The effect of side-chain density on the kinetic parameters of a side-chain-cleaving hemicellulase was determined. Kinetic parameters were based on the rate of Trichoderma reesei α-galactosidase-catalyzed liberation of galactose from galactomannan (guar and locust bean) substrates. The focus enzyme was the predominant α-galactosidase obtained from the fungus'galactomannan-supplemented cell-free culture medium. Substrate concentrations were based on the number of galactosyl moieties per volume reaction mixture. The Km values for the galactomannan substrates differed approximately 4.3-fold (28.36 and 121.16 μM), the more branched substrate having the higher Km. In contrast, the corresponding Vmax values were found to be essentially the same. The results indicate the enzyme preferentially acts at sites of low side-chain density.
Agid:
1413365