| 1. |
- Greffe, L., et al.
(författare)
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Synthesis, preliminary characterization, and application of novel surfactants from highly branched xyloglucan oligosaccharides
- 2005
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 15:4, s. 437-445
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Tidskriftsartikel (refereegranskat)abstract
- A novel class of nonionic, carbohydrate-based surfactants has been synthesized from the plant polysaccharide xyloglucan. Enzymatic hydrolysis of xyloglucan yielded a series of well-defined, highly branched oligosaccharides that, following reductive amination, were readily conjugated with fatty acids bearing C-8 to C-18 chains under mild conditions. The critical micelle concentration, determined by tensiometry and dye-inclusion measurements, showed a typical dependence on acyl chain length and was sensitive to the degree of galactosylation of the head group. Several compounds from this new group of surfactants, especially those with C-14 and C-16 chains, were useful for the extraction of membrane-bound enzyme markers from different plant cell compartments in catalytically active form.
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| 2. |
- Colombani, A., et al.
(författare)
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In vitro synthesis of (1→3)-β-D-glucan (callose) and cellulose by detergent extracts of membranes from cell suspension cultures of hybrid aspen
- 2004
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Ingår i: Cellulose. - 0969-0239 .- 1572-882X. ; 11:3-4, s. 313-327
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to optimize the conditions for in vitro synthesis of (1 --> 3)-beta-D-glucan (callose) and cellulose, using detergent extracts of membranes from hybrid aspen (Populus tremula x tremuloides) cells grown as suspension cultures. Callose was the only product synthesized when CHAPS extracts were used as a source of enzyme. The optimal reaction mixture for callose synthesis contained 100 mM Mops buffer pH 7.0, 1 mM UDP-glucose, 8 mM Ca2+, and 20 mM cellobiose. The use of digitonin to extract the membrane-bound proteins was required for cellulose synthesis. Yields as high as 50% of the total in vitro products were obtained when cells were harvested in the stationary phase of the growth curve, callose being the other product. The optimal mixture for cellulose synthesis consisted of 100 mM Mops buffer pH 7.0, 1 mM UDP-glucose, 1 mM Ca2+, 8 mM Mg2+, and 20 mM cellobiose. The in vitro beta-glucans were identified by hydrolysis of radioactive products, using specific enzymes. C-13-Nuclear magnetic resonance spectroscopy and transmission electron microscopy were also used for callose characterization. The (1-->3)-beta-D-glucan systematically had a microfibrillar morphology, but the size and organization of the microfibrils were affected by the nature of the detergent used for enzyme extraction. The discussion of the results is included in a short review of the field that also compares the data obtained with those available in the literature. The results presented show that the hybrid aspen is a promising model for in vitro studies on callose and cellulose synthesis.
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