• KSBB Journal
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• 제19권2호
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• pp.159-163
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• 2004

$\AA$의 분해능을 가진 Bacillus macerans에서 분리 정제한 cyclodextrin glucanotransferase의 결정 구조를 X-ray를 이용하여 분자 대치법을 사용하여 밝혔다. 정확한 구조는 16.6% ( $R_{free}$ = 20.5%)의 결정학적 R-factor를 가지고 있다. 두 개의 $Ca^{2+}$$_{-}$/ 이온이 점유된 새로운 금속 결합자리는 활성 자리의 도달 채널에서 발견되었다. $Ca^{2+}$$_{-}$/ 이온에 결합하는 음의 하전을 띤 아미노산 잔기들이 많이 밀집되어 있고 이 때, domain A ($\alpha$H에서 아미노산 잔기 283-297)의 중심부에 연결 부분은 $\beta$ 13-$\alpha$G 이었다. $\beta$13-$\alpha$G 부분은 활성 자리의 입구에 위치한 subsite 1에서 -1 과 Tyr260 (subsite 2)사이에 있는 촉매 부위 Glu258을 포함하고 있다. 비록 $\alpha$-CGTase 부류에서 잘 보존되어 있지는 않으나, 새로운 $Ca^{2+}$$_{-}$/ 자리 3a,b가 이 $\alpha$-CGTase의 활성도와 생성물의 특이성에 중요한 역할을 하리라 추측된다.다.

• 한국임상약학회지
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• 제1권1호
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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.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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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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• 제15권3호
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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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• 제6권1호
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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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• 제8권2호
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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.

• 한국식품과학회지
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• 제23권1호
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• pp.93-97
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• 1991

호알칼리성 Bacillus sp. YC-335가 생산하는 CGTase의 효소학적 특성 및 작용반응을 살펴보았다. ${\alpha}-CD,\;{\beta}-CD$ 및 ${\gamma}-CD$로부터 glucosyl residues를 설탕으로 전이시키는 반응에 대한 효소의 최대 반응속도, Vmax 값은 각각 $16.13,\;21.8,\;9.8{\mu}moles glucose/min/mg\;protein$이었으며 Km 값은 각각 1.68, 0.33, 0.37 mM이었다. 효소의 전분 가수분해활성은 여러 당류에 의해 촉진되었으며 특히 전분 가수분해 산물인 maltose와 glucose에 의한 효과가 가장 좋았다. 이 효소는 ${\beta}CD$에 의해 효소의 전분 분해활성이 저해되었으며 비경쟁적 저해형식을 보였다. 또한 전분으로부터 효소작용에 의해 생성된 산물을 총당량법 및 HPLC 분석을 통해 조사한 결과 이 효소는 cyclization 작용 뿐만 아니라 transglycosylation 작용과 disproportionation 작용을 가지는 것으로 확인하였다.

• 한국미생물·생명공학회지
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• 제26권5호
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• pp.442-449
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• 1998

CGTase를 이용한 당전이 xylitol의 합성과 당전이 xylitol의 비피더스균 생육증식 효과에 대한 연구를 수행하였다. 수종의 세균류가 분비하는 CGTase의 xylitol에 대한 당전이능을 비교하였으며, Thermoanaerobacter sp. 유래의 CGTase가 가장 우수한 당전이능을 보였다. 각종 당공여체를 검토한 결과 압출전분이 가장 우수한 결과를 보였으며, 당전이 효소반응의 최적 조건을 검토하였다. 생성된 당전이 xylitol을 활성탄-셀라이트 칼럼 크로마토그래피를 이용하여 분리하여 두 개의 fraction인 F-I, F-II를 얻었다. 이들의 당쇄결합 양상을 FAB mass spectrometer와 $^{13}$C-NMR spectrometer, 그리고 glucoamylase을 이용한 효소소화법을 이용하여 분석한 결과 xylitol에 glucose와 maltose 분자가 $\alpha$-1,4 결합되어 있는 것으로 유추되었다. 얻어진 당전이 xylitol은 xylitol과는 달리 Bifidobacterium breve에 대한 생육촉진효과를 보였다.

• KSBB Journal
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• 제16권2호
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• pp.128-132
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• 2001

발효 배양액으로부터 균체를 제거한 후에 전분파의 흡착성 을 증가시켜주기 위하여 ammonium sulface 25% (w/v), 반응 2시간 정도면 95% 이상의 효소가 전분(힐반전분 1%, wfv)에 홉착됨올 일 수 있었다. 효소 흡착인 경우 일반전분(옥수수 전분)이 흡착율 95% 이상으로 가장 효과적이며 탈착의 경우 (탈착용액 : 증류수)에는 산화천분이 1 회 68%로 가장 효과적이었다. 또한 효소의 홉착 및 탈착에 사용되는 전분익 농도 는 효소 역가 205 U/mL 기준으로 1 % (v/v) 정도면 효소의 흡착 및 탈착에 적당하였다. 효소 흡착외 경우 $4^{circ}C$, 정도에서, 탈착의 경우 온도 $50^{circ}C$, 와 pH 8.0에서 효과적이었다 탈착 용액으로 Iris-buffer가 탈착율 98%로 가장 효과적이었다. 또한 발효배양액으토부터 균체외 제거단계의 유무에 관계없이 전분의 흡착율과 탈착율은 유사하였다.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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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.