• KSBB Journal
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• v.19 no.2
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• pp.159-163
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• 2004

The X-ray structure of the cydodextrin-glucanotransferase of Bacillus macerans was solved by molecular replacement at 2.0 ${\AA}$ resolution. The refined structure has a crystallographic R-factor of 16.6%, (R$\sub$free/ = 20.5%). A new metal binding site occupied by two Ca$\^$2+/-ions was found at an accession channel of the active site. There is a large accumulation of negative charges that bind these Ca$\^$2+/-ions, thereby connecting segment ${\beta}$13-${\alpha}$G (residue 254-276) to the main body of domain A (at ${\alpha}$H, residue 283-297). The segment 313-${\alpha}$G contains the catalytic residue Glu258 between subsite 1 and -1 and Tyr260 (subsite 2) which is located at the entrance of the active site. The Ca$\^$2＋/-site 3a,b may have a major role for the activity and specificity of this CGTase, although it is not even conserved for the a-subclass of CGTases.

• Korean Journal of Clinical Pharmacy
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• v.1 no.1
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• pp.9-14
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• 1991

Inclusion complexes of piroxicam with $\alpha,\;\beta\;and\;\gamma- cyclodextrins$ were prepared and suspended to enhance the bioavailability of piroxicam. A quantitative analysis was employed HPLC for the determination of piroxicam in the rabbit serum after a single oral dose in suspension of piroxicam and each of inclusion complexes of piroxicam with $\alpha,\;\beta\;and\;\gamma- cyclodextrins$, respectively. The bioavailability and serum level of piroxicam exhibited the highest in piroxicam clathrated $\beta-cyclodextrin$ than both piroxicam and the other complexes administered. and the total area under the curve of serum concentration versus time for their inclusion complexes were larger than that of piroxicam.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.306-306
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• 2006

We immobilized and patterned PDA vesicles on solid substrate using micro arrayer, which have moieties to react with chemical and biological materials. Immobilized vesicle system was developed since it possesses many advantages in multiple screening, durable stability, and higher sensitivity. We applied polydiacetylene supramolecules to chemical and biological sensors for detection of ${\alpha}-cyclodextrin$ and E.coli cell selectively. This detection method could be applied as DNA chip, protein chip, and cell chip for multiple screening as well as chemical sensor by modifying the functional groups of diacetylene monomer.

• Journal of Pharmaceutical Investigation
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• v.15 no.3
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• pp.100-112
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• 1985

Dissolution characteristics of flurbiprofen solvent deposited on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, lactose and corn starch were studied to evaluate the pharmaceutical aspects of solvent deposition method where drug was solvent deposited on the surface of excipients. In a solvent deposition system, the drug to excipient ratio and kind of excipient affect much on dissolution rates of flurbiprofen. The solvent deposition system formation was confirmed by scanning electron microscope. By increasing the amounts of matrix, it was possible to enhance the dissolution rate of flurbiprofen solvent deposition system. The amount of flurbiprofen dissolved from ${\beta}-cyclodextrin$ deposition system (1:10) at 60 minutes was enhanced 6.5 times in water and 28 times in simulated gastric juice compared with flurbiprofen alone. Flurbiprofen solvent deposited system (1:10) enhanced dissolution rate greater than inclusion complex and dispersion system.

• Archives of Pharmacal Research
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• v.6 no.1
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• pp.35-44
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• 1983

Interactions between thiamine.HCl and its disulfide derivatives TTFD. TPD and .alpha., .betha. cyclodextrins were investigated. By measuring the H-NMR, C-NMR chemical shifts, the assumption that cyclodextrin may from a inclusion complex with thiamines was supported qualitatively. To calculated the stability constants of them, anion exchange chromatography was applied. The simple, rapid HPLC method was proved to be pertinent thiamine/cyclodextrin system which was chemically unstable and less soluble.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.152-157
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• 1998

To analyze the role of the C and D domains in the cyclization activity of cyclodextrin glucanotransferase (CGTase), two plasmids, pKB1ΔC300 and pKB1ΔD96, were constructed in which DNA regions encoding 100 and 32 amino acids, respectively, from the C and D domains of B. stearothermophilus NO2 CGTase were deleted. The mutated CGTase from the pKBlΔC300 produced much lower amounts of ${\alpha}$-, ${\beta}$-, and $\gamma$-cyclodextrin (CD) than the parental CGTase. However, the mutated CGTase from the pKBlΔD96 showed a similar production pattern of CDs to wild-type CGTase. The production ratios of the ${\alpha}$-, ${\beta}$- and $\gamma$-CDs were not affected by the deletions, when compared to those of parental CGTase. The optimum temperature of the mutated CGTase from the pKBlΔC300 was decreased from $60^{\circ}C$ to $55^{\circ}C$. The optimum pH of the mutated CGTase from the pKB1D96 was shifted from 6.0 to 7.0. The thermostability of the two mutant CGTases were not changed. From these results, it is suggested that the C and D domains are not related to cyclization activity directly because mutant-enzymes deleted C or D domains still possessed their activity. However, they are important for other enzymatic properties such as productivity and pH optimum as a partition of CGTase tertiary structure.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.93-97
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• 1991

The enzymatic properties of purified CGTase from alkalophilic Bacillus sp. YC-335 have been examined. Apparent Vmax values of the enzyme in transferring glycosyl residues ${\alpha}-,\;{\beta}-and\;{\gamma}-cyclodextrin(CD)$ to sucrose were $16.13,\;21.8\;and\;9.8{\mu}moles/min/mg\;protein$, respectively and Km values of the corresponding CD were 1.68, 0.33 and 0.37 mM, respectively. A number of saccharides, specially starch hydrolyzates such as glucose and maltose, could activate the dextrinizing activity of the enzym. However, the dextrinizing activity was inhibited by ${\beta}-CD$. It was found from Lineweaver-Burk plot that the inhibition of CGTase by ${\beta}-CD$ was noncompetitive. High performance liquid chromatographic analysis showed that the enzyme has three kinds of activity ; transglycosylation and disproportionation as well as cyclization.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.442-449
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• 1998

Several transglucosylated xylitols were synthesized using intermolecular transglucosylation reaction of cyclodextrin glucanotransferase (CGTase) and their bifidogenic effects were investigated. The CGTase from Thermoanaerobacter sp. showed the highest transglycosylation activity on xylitol compared to those obtained from other strains. Extruded starch was identified to be the most suitable glucosyl donor for transglucosylation reaction on xylitol molecule by CGTase. The optimum reaction conditions for transglucosylation were also studied using extruded starch as a glucosyl donor. The transglucosylated xylitols were purified by activated carbon column chromatography with ethanol gradient elution from 0 to 18%, and their chemical structures were analyzed by fast atom bombardment mass spectrometer, $\^$13/C-nuclear magnetic resonance spectrometer, and enzyme digestion method. Two transglucosylated xylitol, F-I and F-II, which had one or two glucose molecules attached to maternal xylitol by ${\alpha}$-1,4-linkage, were mainly obtained. F-II showed increased stimulation effect on the growth of Bifidobacterium breve compared to xylitol, indicating the possibility utilized as a new functional alternative sweetners having bifidogenic effects.

• KSBB Journal
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• v.16 no.2
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• pp.128-132
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• 2001

Cyclodextrin glucanotransferase (EC 2.4.1.19 : 1,4-$alpha$-glucan 4-$alpha$-D-(1,4-glucano) transferase, cyclizing; CGTase) was recovered by starch adsorption. The adsorption and desorption of CGTase to starch was studied as a function of pH, temperature, and starch type. The optimal pH, temperature, and starch for adsorption were, 8.0, $4^{circ}C$, and 1% (w/v) corn starch, respectively, per 205 U/mL enzyme activity in the presence of 25% (w/v) ammonium sulfate. The maximum adsorption ratio was 95%. On the other hand, the optimal pH, temperature, and starch type for desorption were 8.0 (tris-buffer), $50^{circ}C$, and oxidized starch, respectively. The maximum desorption ratio was 98% by tris-buffer solution at pH 8.0. The efficiency of adsorption and desorption were affected slightly by the removal of cells from the fermentation broth.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.411-416
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• 2002

Bacillus macerans cyclodextrin glucanotransferase (CGTase) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein, Aga1p. The surface display of CGTase was confirmed by immunofluorescence microscopy and its enzymatic ability to form ${\alpha}$-cyclodextrin from starch. The maximum surface-display of CGTase was obtained by growing recombinant S. cerevisiae at $20^{\circ}C$ and pH 6.0. S. cerevisiae cells displaying CGTase on their surface consumed glucose and maltose, inhibitory byproducts of the CGTase reaction, to enhance the purity of produced cyclodextrins. Accordingly, the experimental results described herein suggest a possibility of using the recombinant S.cerevisiae anchored with bacterial CGTase on the cell surface as a whole-cell biocatalyst for the production of cyclodextrin.