(1→3)-β-d-Glucan Synthase from Sugar Beet

Morrow, David L.; Lucas, William J.

doi:10.1104/pp.81.1.171

Cited by 55 publications

(22 citation statements)

References 9 publications

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“…However, the enzyme kinetic data available in the literature do not unequivocally demonstrate the existence of an allosteric activation in the presence of disaccharides, probably because the experiments were performed with crude extracts and not with purified GS. The enzyme from A. thaliana was weakly stimulated by cellobiose and laminaribiose compared with those of other plant models [23,24,27,42]. In addition, our kinetic studies did not show activation of the allosteric type in the presence of either of these disaccharides (data not shown).…”

Section: Discussionmentioning

confidence: 63%

“…It has been suggested that cellobiose, laminaribiotol and cellodextrins may act as allosteric activators of plant GS [23,27]. However, the enzyme kinetic data available in the literature do not unequivocally demonstrate the existence of an allosteric activation in the presence of disaccharides, probably because the experiments were performed with crude extracts and not with purified GS.…”

Section: Discussionmentioning

confidence: 64%

“…It is possible that, for L. multiflorum and cotton fibres, the increase in the ratio of (1 !4)-b-D-glucans to (1 !3)-b-D-glucans in the presence of Mg 21 is a result of a decrease in GS activity rather than an increase in cellulose synthase activity. In contrast with the situation in other plant models such as mung bean [26], sugar beet [23] and ryegrass [24], Mg 21 inhibited the GS from A. thaliana. This inhibition was observed even in the presence of Ca 21 , in contrast with the GS from soybean where a 10-to 15-fold activation by Ca 21 was observed in the presence of 5 mM Mg 21 [38].…”

Section: Characterization Of the (1 !3)-b-d-glucans Synthesized In Vitromentioning

confidence: 55%

“…We showed that Ca 21 is required for the GS activity of A. thaliana. This is also true for GS from other plant systems [23,27,[37][38][39] except for the developmentally expressed enzyme from Nicotiana alata pollen tubes [40]. In contrast with enzyme preparations from cotton fibres [3], the presence of Mg 21 in the assay mixture brought about strong inhibition of the GS from A. thaliana, without favouring cellulose synthesis.…”

Section: Characterization Of the (1 !3)-b-d-glucans Synthesized In Vitromentioning

confidence: 98%

“…The in vitro activity of plant GS is usually considered to reach its maximum in the presence of b-glucosides or disaccharides such as cellobiose, laminaribiose or gentiobiose [23,24]. The GS from A. thaliana was weakly stimulated by cellobiose (20 mM), the maximum stimulatory effect (10-15%) being observed in the presence of Ca 21 ( Table 1, rows 2 and 5).…”

Section: Determination Of Assay Conditionsmentioning

confidence: 99%

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Biosynthesis of (1→3)‐β‐d‐glucan (callose) by detergent extracts of a microsomal fraction from Arabidopsis thaliana

Him

Pélosi

Chanzy

et al. 2001

European Journal of Biochemistry

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The aim of this work was to develop a biochemical approach to study (1 !3)-b-D-glucan (callose) biosynthesis using suspension cultures of Arabidopsis thaliana. Optimal conditions for in vitro synthesis of callose corresponded to an assay mixture containing 50 mM Mops buffer, pH 6.8, 1 mM UDP-glucose, 8 mM Ca 21 and 20 mM cellobiose. The enzyme was Ca 21 -dependent, and addition of Mg 21 to the reaction mixture did not favour cellulose biosynthesis. Enzyme kinetics suggested the existence of positive homotropic cooperativity of (1 !3)-b-D-glucan synthase for the substrate UDP-glucose, in agreement with the hypothesis that callose synthase consists of a multimeric complex containing several catalytic subunits. Detergents belonging to different families were tested for their ability to extract and preserve membrane-bound (1 !3)-b-D-glucan synthase activity. Cryo-transmission electron microscopy experiments showed that n-octyl-b-D-glucopyranoside allowed the production of micelle-like structures, whereas vesicles were obtained with Chaps and Zwittergent 3-12. The morphology and size of the (1 !3)-b-D-glucans synthesized in vitro by fractions obtained with different detergents were affected by the nature of the detergent tested. These data suggest that the general organization of the glucan synthase complexes and the properties of the in vitro products are influenced by the detergent used for protein extraction. The reaction products synthesized by different detergent extracts were characterized by infrared spectroscopy, methylation analysis, 13 C-NMR spectroscopy, electron microscopy and X-ray diffraction. These products were identified as linear (1 !3)-b-D-glucans having a degree of polymerization higher than 100, a microfibrillar structure, and a low degree of crystallinity.

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Section: Discussionmentioning

confidence: 63%

Section: Discussionmentioning

confidence: 64%

Section: Characterization Of the (1 !3)-b-d-glucans Synthesized In Vitromentioning

confidence: 55%

Section: Characterization Of the (1 !3)-b-d-glucans Synthesized In Vitromentioning

confidence: 98%

Section: Determination Of Assay Conditionsmentioning

confidence: 99%

See 3 more Smart Citations

Biosynthesis of (1→3)‐β‐d‐glucan (callose) by detergent extracts of a microsomal fraction from Arabidopsis thaliana

Him

Pélosi

Chanzy

et al. 2001

European Journal of Biochemistry

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Callose concentration in leaves of field grown Oxalis acetosella (L.) indicates growth impediments

Wissemeier

Rodenkirchen

1994

J Plant Nutrition & Soil

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The Höglwald, located in Bavaria, is a pure Norway spruce stand, where experimental plots which were limed or not were subjected to normal or acid irrigation (Höglwald Experiment). The growth of the forest herb Oxalis acetosella improved greatly with liming. Callose concentration in leaves of Oxalis reflected the lime effect with about a 2.5 times lower callose concentration in the limed compared to unlimed plots. Acid irrigation increased callose concentration only in the unlimed plot. A negative exponential relationship was established between leaflet area and callose concentration. In a Diagnostic Field Fertilization Experiment in the vicinity of the Höglwald Experiment, Ca and Mg were applied either as carbonate or sulphate and Mn and Si added to experimental plots. In this experiment, it was demonstrated that it was not liming per se, but the application of Ca, that greatly increased the growth of Oxalis. Again, there was a negative correlation between leaflet area and callose concentration in leaves. Chemical analysis of leaves revealed that a Mn concentration > 3.5 mg (g DW)−1 and a Mg concentration > 10 mg (g DW)−1 led to increased callose concentration.

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1,3-β-Glucan synthase

Springer Handbook of Enzymes

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(1→3)-β-d-Glucan Synthase from Sugar Beet

Cited by 55 publications

References 9 publications

Biosynthesis of (1→3)‐β‐d‐glucan (callose) by detergent extracts of a microsomal fraction from Arabidopsis thaliana

Biosynthesis of (1→3)‐β‐d‐glucan (callose) by detergent extracts of a microsomal fraction from Arabidopsis thaliana

Callose concentration in leaves of field grown Oxalis acetosella (L.) indicates growth impediments

1,3-β-Glucan synthase

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