D-Glucanotransferases

An acid cyclodextrin D-glucanotransferase from an alkalophilic Bacillus sp. exhibits a specificity similar to those of the transferases from B. circulans and B. macerans, although different proportions of cyclohexa-, cyclohepta-, and cyclo-octa-amyloses are formed. The cyclodextrin D-glucanotransferase from an alkalophilic Bacillus sp. has been used, either alone or in combination with pullul-anase, to produce cyclohepta-amylose. A succinylated derivative of this cyclodextrin D-glucanotransferase has been immobilized, with retention of activity, by adsorption onto a vinylpyridine polymer. 

Cyclodextrin D-Glucanotransferases.—The neutral cyclodextrin D-glucano-transferase from an alkaliphilic Bacillus species has been purified by adsorption onto starch, ion-exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. The enzyme (mol. wt. 8.5—8.8 x 10 in the presence of sodium dodecyl sulphate) is most active at pH 7 and 50 °C, is thermally stable, and converts starches and glycogens principally into cyclohepta-amylose. 

500 Nakamura and K. Horikoshi, Agric. and Biol. Chem. Japan), 1976, 40, 1785. 

A purified extracellular cyclodextrin D-glucanotransferase (pH optimum 4.6, pi 5A, mol. wt. 8.8 x 10 ) from an alkaliphilic Bacillus species has been shown to be a single homogeneous protein by polyacrylamide gel electrophoresis and ultracentrifugation. The Km values for cyclohexa-, cyclohepta-, and cyclo-octa-amyloses at a constant concentration of sucrose are 5.88, 0.39, and 0.25 mmol 1, respectively. The enzyme converted starch, amylopectin, glycogen, and amylopectin j8-limit dextrin into cyclodextrins. 

The transglycosylation reactions catalysed by cyclodextrin D-glucano-transferases from B. megaterium and B. macerans have been shown to differ towards such acceptors as D-glucose, maltose, maltotriose, and sucrose. It was suggested that cyclodextrin D-glucanotransferase may transfer D-glucosyl residues from starch, as well as from cyclodextrins, to an acceptor. 

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Cyclomaltodextrin D-Glucanotransferases. — Intermolecular transglycosylation of cyclomaltodextrin glycosyltransferase from Bacillus megaterium has been exam-... 

The conversion of starch into cyclohepta-amylose by soluble or immobilized cyclodextrin D-glucanotransferases and the ability of a-amylases to convert starch into some products by a non-hydrolytic (transglycosylation) pathway have been reported.The production of single-cell protein from starchy wastes has been discussed. 

Cyclodextrin D-Glucanotransferases.—A succinyl derivative has been prepared from the cyclodextrin D-glucanotransferase isolated from an alkalophilic Bacillus species. ... 

An immobilized form of cyclodextrin D-glucanotransferase catalysed the conversion of starch into cyclohepta-amylose in a yield of 46 %, without significant loss of enzymic activity a yield of 52% was achieved when pullulanase was also added. ... 

Cyclodextrin n-Glucanotransferase.—Cyclodextrin D-glucanotransferase has been prepared from culture fluids of a Bacillus species by adsorption onto corn starch, fractional precipitation with ammonium sulphate, ion-exchange chromatography, and gel filtration. Disc electrophoresis and isoelectric focusing separated the enzyme into two fractions (p7 6.07 and 6.80), which were able to synthesize cycloamyloses (predominantly cyclohepta-amylose) from starch. The enzymes differ from the cyclodextrin o-glucanotransferase from B. macerans, notably in their actions on starch. 

Cyclobuxine-D, 2 104 P-Cyclocitral, 24 570 Cyclocitronellene acetate, 24 488 a-Cyclocitrylidenebutanone, 24 565 Cyclodehydrating agents, 20 276 Cyclodemol, 24 488 P-Cyclodextrin, 4 715 Cyclodextrin glucanotransferase, 24 48 Cyclodextrin glycosyltransferase, 4 715 Cyclodextrin inclusions, 74 183 Cyclodextrin inclusion compounds, 74 166-167... 

Some starch-deficient mutants of Arabidopsis and Chlamydomonas have been shown to be defective in a-l,4-glucanotransferase activity. The enzyme is also known as D-enzyme. The reaction it catalyzes is as follows ... 

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