• 생명과학회지
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• 제12권1호
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• pp.77-86
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• 2002

토양으로부터 chitinase를 생성하는 균주를 분리하여 동정한 결과 Bacillus subtilis로 판명되었으며, 분리한 균주를 Bacillus subtilis JK-56이라 명명하였다. B. subtilis JK-56의 chitinase 생산 최적 조건을 검토한 결과 1% chitin, 0.5% polypeptone, 0.1% KCI, 0.05% MnS $O_4$.4$H_2O$이며 초발 pH 7.0, 배양온도 37$^{\circ}C$에서 가장 많은 효소를 생산하였다. 본 균주가 생산하는 chitinase를 정제하기 위해서 native-PAGE를 이용해 효소활성 band를 확인한 결과, 1개의 강한 활성 band와 2개의 약한 활성 band를 가지는 isozyme으로 확인되었다. 확인된 isozyme을 정제한 결과, isozyme 중 1개의 강한 활성 band를 정제하였고 정제된 효소를 Chi-56A라고 명명하였다 Chi-56A의 효소 특성에 관해서 실험한 결과 분자량은 약 53kDa, pI는 4.3으로 확인되었다. 본 효소는 $65^{\circ}C$까지 상당히 안정하였으며 효소의 최대활성 온도도 $65^{\circ}C$로 확인되는 등 열에 대해 상당히 안정한 효소로 확인되었다. Collidal chitin에 대한 정제효소 Chi-56A의 $K_{m}$ 값은 17.33g/L였다. 그리고 pH 6.0에서 최대의 활성을 나타내었고, 산성범위보다 알칼리범위에서 안정한 것으로 나타났다. 또한 $Mn^{2+}$ 존재 하에서 높은 활성을 나타내었고 C $O^{2+}$와 $Mg^{2+}$ 존재 하에서도 활성이 약간 증가한 반면에 H $g^{2+}$ 존재 하에서는 상당한 저해를 받았다. Chito 올리고당에 대한 분해 산물을 HPLC로 확인해 본 결과 짝수개의 올리고당의 분해산물은 (GlcNAc)$_2$만을 생산하였고 홀수개의 올리고당에 대해서는 GlcNAc와 (GlcNAc)$_2$를 생산하는 것으로 비환원성 말단으로부터 이당체인 diacetyl chitobiose ((GlcNAc)$_2$)를 생산하는 exo형 chitinase로 추정 된다.

• 한국미생물·생명공학회지
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• 제30권4호
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• pp.312-319
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• 2002

저온성 균인 Sporosarcina psychrophilia의 염색체 DNA를 추출하여 Sau3AI으로 부분 절단하고 pUC19 vector에 ligation 시킨 후, Escherichia coli pyrB mutant 균주에 형질전환하여 uracil이 없는 AB배지에서 생존하는 균주를 선택한 후, 그 plasmid를 분리하여 pSMI과 pSM2라고 명명하였다. 두 plasmid의 염기배열을 결정한 결과 pSM2 insert DNA는 pSMl insert DNA 부분을 포함하는 2,606 nucleotide 단편이었다. 염기서열을 분석하였을 때 이것은 1개의 완전한 open reading frame(ORF)과 2개의 부분 ORFs를 포함하고 있었다. 두 번째 위치한 완전한 ORF는 Bacillus caldolyticus aspartate transcarbamylase(pyrB)와 아미노산 서열 수준에서 59% 상동성을 보였고, 첫 번째와 세 번째 위치한 부분적 ORFs는 각각 Bacillus속의 uracil permease(pyrP)와 dihydoorotase(pyrC)와 높은 상동성을 보였다. 그리고 pyrB와 pyrP사이에 intergenic 부분에는 잠재적인 terminator, antiterminator, anti-antiterminator 구조를 포함하고 있었다. 이러한 결과는 S. psychrophilia pyrimidine 생합성에 관련된 유전자들은 다른 Bacillus속에서 알려진 바와 같이 유전자군을 형성하고 있을 것으로 추정했다. S. psychrophilia pyrB 유전자의 생성물을 과다발현 시키고 정제해서 그 단백질을 SDS-PAGE로 확인한 결과 27 kDa 부근에서 band를 확인할 수 있었으며, 정제한 단백질도 ATCase 효소활성을 지니고 있었다.

• 한국어병학회지
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• 제8권1호
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• pp.37-46
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• 1995

H. cunea nuclear polyhedrosis virus (HcNPV) 의 polyhedrin 아미노산 및 polyhedrin gene 의 염기서열을 분석하였다. Polyhedrin 은 SDS-PAGE 상에서 3개의 polypeptide band 가 나타났고 주요 polypeptide 는 약 25 Kd 의 분자량을 갖고 있었다. 또한 polyhedrin 은 17 개의 다른 아미노산으로 구성되어 있었다. HcNPV DNA를 EcoRI 효소로 절단하여 $\alpha^{32}P$로 labelling 된 Autographa californica (AcNPV) polyhedrin gene cDNA 의 probe DNA를 이용하여 hybridization 한 결과 polyhedrin gene은 EcoRI 절편들중 H 절편에 양성반응을 나타냈다. 또한 polyhedrin gene 을 포함하고 있는 EcoRI-H 절편을 pUC8 벡터에 cloning한 다음 이를 hPE-H라고 이름하였다. HcNPV genome DNA 의 promoter 부위를 sequence한 결과 TATA box의 염기배열은 polyhedrin gene 전사 개시위치로부터 위쪽으로 -79 bp 의 5' flanking 부위에서 발견되었다. polyhedrin gene 내 CAAT box는 TATA box 측면 염기 배열에서 나타나지 않았고, 4개의 tandem repeat 5'-CTAATAT-3' 와 5'-TAAATAA-3'의 염기는 polyhedrin gene내 전이 개시 위치로 부터 위쪽으로 -141 과 -108 bp 또는 -83 bp 부위에 존재하였으며, 다른 하나는 전이 개시위치로 부터 아래쪽으로 -52 bp 부위에서 발견되었다. 그리고 polyhedrin gene 내 전이 개시위치로 부터 위쪽으로 -141 bp 부위는 다량의 AT (78%) 염기가 존재하였다. 또한 polyhedrin 의 개시 coding region 은 ATG 였고 종결 coding region은 TAA 였다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.16-25
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• 2001

A genomic library of biphenyl-degrading strain Comamonas sp. SMN4 was constructed by using the cosmid vector pWE15 and introduced into Escherichia coli. Of 1,000 recombinant clones tested, two clones that expressed 2,3-dihydroxybiphenyl 1,2-dioxygenase activity were found (named pNB 1 and pNB2). From pNB1 clone, subclone pNA210, demonstrated 2,3-dihydroxybiphenyl 1,2-dioxygenase activity, is isolated. 2,3-Dihydroxybiphenyl 1,2-dioxygenase (23DBDO, BphC) is an extradiol-type dioxygenase that involved in third step of biphenyl degradation pathway. The nucleotide sequence of the Comamonas sp. SMN4 gene bphC, which encodes 23DBDO, was cloned into a plasmid pQE30. The His-tagged 23DBDO produced by a recombinant Escherichia coli, SG 13009 (pREP4)(pNPC), and purified with a Ni-nitrilotriacetic acid resin affinity column using the His-bind Qiagen system. The His-tagged 23DBDO construction was active. SDS-PAGE analysis of the purified active 23DBDO gave a single band of 32 kDa; this is in agreement with the size of the bphC coding region. The 23DBDO exhibited maximum activity at pH 9.0. The CD data for the pHs, showed that this enzyme had a typical a-helical folding structures at neutral pHs ranged from pH 4.5 to pH 9.0. This structure maintained up to pH 10.5. However, this high stable folding strucure was converted to unfolded structure in acidic region (pH 2.5) or in high pH (pH 12.0). The result of CD spectra observed with pH effects on 23DBDO activity, suggested that charge transition by pH change have affected change of conformational structure for 23DBDO catalytic reaction. The $K_m$ for 2,3-dihydroxybiphenyl, 3-metylcatechol, 4-methylcatechol and catechol was 11.7 $\mu$M, 24 $\mu$M, 50 mM and 625 $\mu$M.

• 한국정보처리학회논문지
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• 제3권7호
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• pp.1669-1679
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• 1996

In this paper, we address the problem of how to replace huffers in multimedia database systems with time-varying skewed data access. The access pattern in the multimedia database system to support audio-on-demand and video-on-demand services is generally skewed with a few popular objects. In addition the access pattem of the skewed objects has a time-varying property. In such situations, our analysis indicates that conventional LRU(least Recently Used) and LFU(Least Frequently Used) schemes for buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural suited. We propose a new buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural Networks)using a neural network for multimedia database systems with time-varying skewed data access. The major role of our neural network classifies multimedia objects into two classes:a hot set frequently accessed with great popularity and a cold set randomly accessed with low populsrity. For the classification, the inter-arrival time values of sample objects are employed to train the neural network.Our algorithm partitions buffers into two regions to combine the best roperties of LRU and LFU.One region, which contains the 핫셋 objects, is managed by LFU replacement and the other region , which contains the cold set objects , is managed by LRUreplacement.We performed simulation experiments in an actual environment with time-varying skewed data accsee to compare our algorithm to LRU, LFU, and LRU-k which is a variation of LRU. Simulation resuults indicate that our proposed algorthm provides better performance as compared to the other algorithms. Good performance of the neural network-based replacement scheme means that this new approach can be also suited as an alternative to the existing page replacement and prefetching algorithms in virtual memory systems.

• Biomolecules & Therapeutics
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• 제4권1호
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• pp.103-109
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• 1996

To investigate the effect of the third intracellular loop (i3 loop) peptide of human $\beta$$_2$-adrenergic receptor on receptor agonist binding, we expressed third intracellular loop region of human $\beta$$_2$-adrenergic receptor as glutathione S-transferase fusion protein in E. coli. DNA fragment of the receptor gene which encodes amino acid 221-274 of human $\beta$$_2$-adrenergic receptor was amplified by polymerase chain reaction and subcloned into the bacterial fusion protein expression vector pGEX-CS and expressed as a form of glutathione-S-transferase (GST) fusion protein in E. coli DH5$\alpha$. The receptor fusion protein was identified by SDS-PAGE and Western blot using monoclonal anti-GST antibody. The fusion protein expressed in this study was purified to an apparent homogeneity by glutathione Sepharose CL-4B affinity chromatography. The purified i3 loop fusion proteins at a concentration of 10 $\mu\textrm{g}$/ι caused right shift of the isoproterenol competition curve of [$^3$H]Dihydroalprenolol binding to hamster lung $\beta$$_2$-adrenergic receptor indicating lowered affinity of isoproterenol to $\beta$$_2$-adrenergic receptor possibly due to the uncoupling of receptor and G protein in the presence of the fusion protein. The uncoupling of receptor and G protein suggests that i3 loop region plays a critical role on $\beta$$_2$-adrenergic receptor G protein coupling.

• KIEAE Journal
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• 제13권2호
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• pp.113-122
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• 2013

On July 2004, the brand new CASBEE for construction (Brief version) has completed while trying to highlight and improve major items adequate for each region's characteristics in Japan; at the same time, from the start of NAGOYA CITY (operated since April 2004) to the point of May 2011, it has been mandatory for specified size buildings in 23 regions by law. Evaluation sheet of CASBEE is published on each region's home page and various genre of information on building evaluation which is scheduled to be completed by 2016 and is for 5-6 years of quantity is accumulated until October 2012. It is good study resource to verify how new buildings being evaluated are closely match with CASBEE's original purport (eco-friendly, energy efficiency, publicity etc). Particularly, for Japan's multi-family housing where small sized mid to high level single housing type is majority in city, it is an important point that improved performance on eco-friendly buildings have more value in city rather than suburb. Categorized score through evaluation is a resource to confirm the latest trend of multi-family housing built in congested city; on the other hand, demand of the time can be recognized by the score focused on category. It is meaningful resource to determine the adequacy of evaluated items and the degree of reality.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.302-309
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• 2005

Phytopathogenic Pectobacterium carotovorum subsp. carotovorum (Pcc) LY34 secretes multiple isozymes of the plant cell wall degrading enzyme endoglucanases. We have cloned a third cel gene encoding CMCase from Pcc LY34. The structural organization of the celC gene (AY188753) consisted of an open reading frame (ORP) of 1,116 bp encoding 371 amino acid residues with a signal peptide of 22 amino acids within the NH$_2$-terminal region of pre-CelC. The predicted amino acid sequence of CelC was similar to that of Peetobaeterium ehrysanthemi Cel8Y (AF282321). The CelC has the conserved region of the glycoside hydrolase family 8. The apparent molecular mass of CelC was calculated to be 39 kDa by CMC-SDS-PAGE. The cellulase­minus mutant of Pee LY34 was as virulent as the wild-type in pathogenicity tests on tubers of potato. The results suggest that the CelC of Pce LY34 is a minor factor for the pathogenesis of soft-rot.

• Archives of Pharmacal Research
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• 제19권4호
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• pp.275-279
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• 1996

To study the functional roles of dopamine receptors, we decided to raise antibodies against these proteins. To make antigen, we expressed the whole 3rd cytoplasmic loop of dopamine receptors in a fusion protein with glutathione-S-transferase (GST). $For D_2\; and\; D_3$ receptors, it was successful to express and purify fusion proteins for the whole 3rd cytoplasmic loops. However, we could not express the fusion protein for the whole 3rd cytoplasmic loop of $D_4$ dopamine receptor in the bacteria. To study the causes that prevent the bacterial expression of the GST-fusion protein of the 3rd cytoplasmic loop of $D_4$ dopamine receptor, we conducted more detailed studies on $D_4$ dopamine receptor. To locate the region which prevents bacterial expression, we made sequential constructs in the 3rd cytoplasmic loop decreasing the size step by step, and confirmed their expressions in the SDS PAGE. It was found that certain regions of 3rd cytoplasmic loop of $D_4$ dopamine receptor, located in N-terminal side of the 3rd cytoplasmic loop of $D_4$ dopamine receptor suppress the bacterial expression of fusion protein.

• BMB Reports
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• 제36권5호
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• pp.514-519
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• 2003

The ribonucleotide reductase (RR) 2 gene of the HSV-2 strain G was cloned, sequenced, and expressed in an E. coli cell. The RR2 gene was located on the PstI 2.4 kb fragment, which was cloned and sequenced. The ORF of the gene was 1,011 bp and its termination codon was TAG; also, the CATATAA sequence was present in the promoter of the RR2 gene. A Poly A signal sequence (AATAAA) was found in the 3'-noncoding region. The RR2 proteins that were produced in the E. coli and Vero cells were confirmed using a Western blot analysis. SDS-PAGE revealed that the molecular weights of the fusion-RR2 that was produced in the E. coli cells were approximately 24 kDa and 38 kDa in the Vero cells. The RR2 proteins were soluble. The differences in the molecular weights might be due to modifications in the Vero cells.