Amyloses cyclo

This discussion has emphasized the idea that the interaction of the cyclo-amyloses with organic substrates is more favorable than the interaction of the individual molecules with water. In the sense that the driving force for the inclusion process appears as a favorable enthalpy of association, this may be thought of as an atypical hydrophobic interaction. 

Takeo and coworkers93 examined the 13C-n.m.r. spectra of peracetylated cyclo-hexa-, -hepta-, and -octa-amyloses [consisting of 6, 7,... 

Hammett substituent constant, effect of cyclo-amyloses on, in hydrolysis of phenyl esters, 23 222... 

All chapters/subjects that were also in the previous edition have been updated. Chapters have been added on the biochemistry and molecular biology of starch biosynthesis, structural transitions and related physical properties of starch, and cyclo-dextrins. There are two chapters on the structural features of starch granules that present not only advances in understanding the organization of starch granules, but also advances in understanding the fine structures of amylose and amylopectin, both of which are based on techniques that have been developed since 1984. 

Watanabe, H., Nishimoto, T., Sonoda, T., Kubota, M., Chaen, H., and Fukuda, S. 2006c. An enzymatically produced novel cyclomaltopentaose cyclized from amylose by an a-(l-6)-linkage, cyclo-(-6 -a-D-Glcp-(l-4)-a-I)-Glcp-(l-4)-a-I)-Glcp-(l-4)-a-D-Glcp-(l-4)-a-D-Glcp-(l-). Carb.. Res., 341, 957-963. 

Final concentrations of amylose, TNS, and KGl were 0.1 %, 5 X 10 5 M, and 0.2 M, respectively, imless otherwise specified. The measured solutions of P-limit dextrin and simylopectin were prepared by the same method as the preparation of amylose solution. In the case of cyclo-dextrins, they were dissolved directly in the KGl aqueous solution at pH 7. 

Sets of decay parajneters obtained for TNS aqueous solution with amylose and its related compounds, including a-, 3-, andy-cyclo-dextrins, are summarized in Table I. The values of lifetimes for three kinds of polysaccharides are similar, but the relative... 

Studies of the hydrolyses of cyclohexa-, cyclohepta-, and cyclo-octa-amyloses by Taka-amylase A (one of the a-amylases from Aspergillus oryzae) indicated that each cycloamylose binds to the same active site of the enzyme. Since there is little difference in the respective AG, Af/, and AS values for enzymic hydrolysis of these cycloamyloses, their binding modes appear to be similar. The extent of multiple attack on the cycloamyloses was not affected by temperature. A 4-phenylazobenzoyl derivative of Taka-amylase A has been used to investigate the active site of the enzyme. A. oryzae a-amylase has a synergistic effect on the action of the glucoamylase from A. awamori var. kawachi ... 

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. 

Conditions for the maximum yield of extracellular a-amylase from Bac-teroides amylophilus have been reported. Isoelectric focusing and polyacrylamide gel electrophoresis demonstrated the presence of six isoenzymes one of these was purified by ion-exchange chromatography and gel filtration. This enzyme (pH optimum 6.3, temperature optimum 43 °C, pH stability range 5.8—7.5, p7 4.6, mol. wt. 9.2 x 10 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis) was inhibited by cyclo-hexa and hepta-amyloses, phenyl a-D-glucopyranoside, and Hg + whereas Ca + and Co were strong activators. The relative rates of hydrolysis of amylose, soluble starch, amylo-pectin, and dextrin were 100, 97, 92, and 60%, respectively (Am values 18.2, 18.7, 18.2, and 16.7 [xmol D-glucosidic bonds 1, respectively). 

In the biological synthesis of ( clohexa-, cyclohepta-, and cyclo-octa-amyloses by the action of enzymes from Bacillus megaterium and B. macerans on P C]-starch, the amounts of each cycloamylose formed were determined by measurement of the radioactivity. The cycloamyloses were produced by the respective enzymes in the ratios 1 2.4 1 and 2.7 1 1 and the ratios were largely independent of the pH of the media. Cyclohexa- and cyclo-octa-amyloses were produced directly from starch and not by way of cyclohepta-amylose. 

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 fluorescence of 6-/ -toluidinylnaphthalene 2-sulphonate was appreciably enhanced in solutions of cyclohexa-, cyclohepta-, and cyclo-octa-amyloses. The increased fluorescence was used to study the kinetics of inhibition by maltose and cyclohexa-amylose of the hydrolysis of cyclohepta-amylose by ot-amylase. The binding of cyclohepta-amylose to a-amylase has been studied. ... 

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