WOZNIEWSKI, T and BLASCHEK, W and FRANZ, G (1992) ISOLATION AND CHARACTERIZATION OF AN ENDO-BETA-MANNANASE OF LILIUM-TESTACEUM BULBS. PHYTOCHEMISTRY, 31 (10). pp. 3365-3370. ISSN 0031-9422,
Full text not available from this repository.Abstract
The bulbs of Lilium testaceum contain large quantities of a storage beta-1,4-glucomannan (beta-1,4-GM) with a Man to Glc ratio of 7 to 3 and a M(r) of 230 000. The mobilization of the beta-1,4-GM as well as of the accompanying starch proceeds during germination of the Lilium bulbs. Enzymes responsible for the breakdown of the reserve polysaccharides were shown to be alpha-amylase, alpha-glucosidase, beta-mannosidase, beta-glucosidase and endo-beta-mannanase. A crude enzyme preparation hydrolysing the Lilium GM was isolated from germinated Lilium bulbs and enzymes were separated by ion exchange chromatography (IEC) on DEAE-Sephacel and by gel permeation chromatography (GPC) on Superose(TM)12. The purified beta-mannanase exhibited optimal activity at pH 4.5 and an optimal temperature of 40-degrees. The M(r) of the beta-mannanase was estimated to be 33 000 by gel filtration, the K(m) and V(max) values were 6.17 x 10(-3) M and 16.1 X 10(-3) nkat, respectively. The activity of the beta-mannanase was determined by measuring the reduction of the viscosity and the enhancement of reductive equivalents in beta-1,4-GM solutions. The GM-hydrolysis proceeded by a random mechanism. The beta-1,4-GM degradation products were identified as Man, Glc, a number of beta-1,4-manno- and glucomanno-oligosaccharides and a remarkable amount of a small M(r) (3000) GM fraction with an identical Man to Glc ratio as in the genuine GM.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | POLYSACCHARIDES; GLUCOMANNAN; LILIUM-TESTACEUM; LILIACEAE; BULBS; GLUCOMANNAN MOBILIZATION; ENDO-BETA-MANNANASE |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:44 |
| URI: | https://pred.uni-regensburg.de/id/eprint/54369 |
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