Enzymes carbohydrate esters

Esterification. The hydroxyl groups of sugars can react with organic and inorganic acids just as other alcohols do. Both natural and synthetic carbohydrate esters are important in various apphcations (1,13). Phosphate monoesters of sugars are important in metabohc reactions. An example is the enzyme-catalyzed, reversible aldol addition between dibydroxyacetone phosphate [57-04-51 and D-ylyceraldehyde 3-phosphate [591-57-1 / to form D-fmctose 1,6-bisphosphate [488-69-7],... 

Because carbohydrates are so frequently used as substrates in kinetic studies of enzymes and metabolic pathways, we refer the reader to the following topics in Ro-byt s excellent account of chemical reactions used to modify carbohydrates formation of carbohydrate esters, pp. 77-81 sulfonic acid esters, pp. 81-83 ethers [methyl, p. 83 trityl, pp. 83-84 benzyl, pp. 84-85 trialkyl silyl, p. 85] acetals and ketals, pp. 85-92 modifications at C-1 [reduction of aldehydes and ketones, pp. 92-93 reduction of thioacetals, p. 93 oxidation, pp. 93-94 chain elongation, pp. 94-98 chain length reduction, pp. 98-99 substitution at the reducing carbon atom, pp. 99-103 formation of gycosides, pp. 103-105 formation of glycosidic linkages between monosaccharide residues, 105-108] modifications at C-2, pp. 108-113 modifications at C-3, pp. 113-120 modifications at C-4, pp. 121-124 modifications at C-5, pp. 125-128 modifications at C-6 in hexopy-ranoses, pp. 128-134. 

Immobilized HRP on different cinnamic carbohydrate esters The thermostability of the immobilized HRP was greater than that of the free enzyme and also showed great [51,52]... 

FIGURE 6.3 Peptide, enzyme, and carbohydrate esters of cotton cellulose that form bioconjugates creating biologically active cotton textile surfaces. 

Hartley, R.D. Jones, E.C. 1976. Carbohydrates and carbohydrate esters of ferulic acid released from cell walls of Lolium multiflorum by treatment with celluotyic enzymes. Phytochem. 15 305-307. 

The enhancement of enzyme yields by carbohydrate esters (Table 3) may be due, in part, to their surfactant properties. This is certainly true of sucrose monopalmitate, which has been found to increase yields, not only of invertase, but of many other enzymes listed in Table 4. Both Tween 80 and sucrose monopalmitate are nonionic surfactants relatively nontoxic to the organisms tested. At first, it was believed that only this type of surfactant possessed the stimulating effect. Later sodium oleate proved superior to Tween 80 for producing cellulase by some fungi. The anionic surfactants tend to be more toxic than the nonionics. The cationic agents, which are even more toxic, have not been found useful in this work. 

The application of lipases to the preparation of sugar esters has been reviewed, and a short section with 18 refs, on the formation and hydrolysis of carbohydrate esters is included in a review on the use of esterolytic and lipolytic enzymes in organic synthesis. ... 

Janssen, A. E. M., Klabbers, C., Franssen, M. C. R. and Vantriet, K. (1991) Enzymatic-synthesis of carbohydrate esters in 2-p5urolidone. Enzyme Microb. Technol., 13, 565-572. Inada, Y., Nishimura, H., Takahashi, K. et al. (1984) Ester synthesis catalysed by polyethylene glycol-modified lipase in benzene. Biochem. Biophys. Res. Commim., 122, 845-850. 

One of the reactions in the metabolism of carbohydrates by the glycolytic pathway is a type of aldol addition. In this reaction D-fructose (as the 1,6-diphosphate ester) is formed from D-glyceraldehyde and 1,3-dihydroxypro-panone (both as monophosphate esters). The process is readily reversible and is catalyzed by an enzyme known as aldolase ... 

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