• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.301-305
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• 2002

The gene (ppaT) encoding Thermus caldophilus GK24 pyrophosphatase (Tca pyrophosphatase) was cloned and sequenced. The gene was found to contain an open reading frame encoding 175 amino acids with a calculated mass of 19,155 Da. The ppaT gene was expressed under the control of the tac promoter in Escherichia coli. The recombinant Tca pyrophosphatase was purified 21.4-fold with $56\%$ yield and specific activity of 25.7 U $mg^-1$, following a combination of heating (to denature the E. coli proteins) and one step of DEAE-Sephacel column chromatography. The native enzyme was found to have an approximate molecular mass of 110,000 Da and consisted of six subunits. The enzyme exhibited maximal activity at pH of 8.0-8.5 and was stable at $80-90^{\circ}C$. A divalent cation was absolutely required for the enzyme activity, with $Mg^2+$. being the most effective.

• KSBB Journal
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• 제14권6호
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• pp.677-681
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• 1999

계란의 난황으로부터 유래한 IgY의 분리와 정제과정이 흐름을 정리한 결과, 난황에서의 수용성 단백질의 분리단계가 단백질의 수율을 증가시키는데 가장 큰 영향을 미치는 것으로 판단되었다. 본 연구에서는 자연 침전방법을 통하여 실험하였는데 수율의 증가를 위해서는 원심분리와 같이 수용성 단백질의 양을 많이 얻을 수 있는 방법이 필요하고, 인지질이나 lipoprotein등의 성분의 제거효율을 높이기 위해서는 x-carrageenan등과 같은 natural gum성분의 첨가와 같은 방법이 필요하다. 그러므로 자연침전을 이용하여 수율의 증가측면과 비용의 절감의 효과를 얻을 수 있었다. 보다 효율적인 IgY의 분리를 위해서는 초기 단계에서 수율의 극대화와 불순성분 제거의 최대화가 동시에 요구되고 있다. 전처리 후의 시료를 이용하여 이온교환 크로마토그래피와 gel filtration chromatography를 통해 순도 90% 이상의 IgY를 얻을 수 있었다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.136-136
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• 1998

L-asparaginyl and L- aspartyl residues in proteins are subject to spontaneous degradation reactions generating isomerized and racemized aspartyl derivatives. Proteins containing L-isoaspartyl and D-aspartyl residues usually have altered structures and diminished biological activities. These residues can be recognized and be repaired to normal L-aspartyl residues by protein L-isoaspartyl methyltransferase(PIMT), which is present at high levels in testis. Although testicular PIMT have been shown to be involved in either sperm motility or sperm maturation, it may play an important role in the repair of damaged sperm proteins during the prolonged period of epididymal transport and storage. In the present study, as a initial step toward elucidating the function of protein carboxylmethylation in testis, we purified PIMT from porcine testicular cytosol as a momeric 27,000 Da species by ammonium sulfate precipitation, DEAE-sephacel chromatography, SAH-liganded affinity chromatography, and gel filtration chromatography. The optimum pH for the reaction was 6.0. $K_{m}$ values of the enzyme for the S-adenosyl-L-methionine (SAM), synthetic oligopeptide(VYP-L-isoD-HA) and histone type II-As were 1.0 ${\mu}$M, 33.2 ${\mu}$M and 276 ${\mu}$M respectively. Consequently, properties of the porcine testicular PIMT is similar to that of other mammalian PIMTs.

• 약학회지
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• 제37권2호
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• pp.129-135
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• 1993

Serratia sp. Y-4 was isolated from soil. Many characteristics of the strain and optimum cultivation condition for protease production were investigated.,The protease from Serratia sp. Y-4 was purified and studied for the properties of the enzyme. The isolated strain was identified to the genus Serratia. The strain was cultivated in 1%-casein, 0.5%-Na$_{3}$PO$_{4}$.7H$_{2}$O, 0.1%-NaCl, 0.05%-KCI, 0.02%-MgSO$_{4}$.7H$_{2}$O, 0.02%-CaCl$_{2}$.2H$_{2}$O, 0.02%-ZnSO$_{4}$.7H$_{2}$O, 0.02%-MnCl$_{2}$.4H$_{2}$O and 0.5%-soy bean oil at pH 7.0 for 35 hrs. The enzyme was purified about 5.89 fold from the culture broth with 31.1% recovery and 19,613 u/mg through ultrafiltration, ammonium sulfate, DEAE-sephacel and Superose-12 chromatography. The purified enzyme was identified as one band by isoelectric focusing, SDS- and native-PAGE. It has maxium activity at $37^{\circ}C$ and pH 9.0. Molecular weight of it is approx. 50 kD and pl is about 6.70. Its Km value for casein was 20 mg/ml. 5 mM-EDTA, 5mM-SDS, Ag$^{+1}$, Cu$^{+2}$, Hg$^{+2}$ and Pb$^{+2}$ inhibited the enzyme.

• 동아시아식생활학회지
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• 제9권2호
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• pp.200-206
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• 1999

Salmonella typhimurium 항원에 면역된 산란계의 계란항체(IgY)생산 및 증가를 측정한 결과, 산란계가 이들 항원에 면역반응을 일으켜 2주 후 혈청과 난황에서 정상군에 비하여 뚜렷한 항체가 생성능을 보였으며. 혈청내의 IgG생성에 비하여 계란항체(IgY)의 생성이 다소 낮은 것으로 나타났다. 혈청 및 난황내의 단백질 함량은 정상군에 비하여 약간 높은 경향을 나타내어 산란계의 혈청 및 난황내의 단백질이 이들 항원에 의하여 증가하는 것으로 나타났다. DEAE-Sephacel column을 통과한 분획은 두 개의 peak를 나타내었다. 각 분획의 IgY농도를 ELISA법으로 확인한 결과 시험관 350-635$m\ell$에 해당되는 두번째 peak에서 대부분 측정되었다. 분리 정제된 IgY의 분자량을 측정한 결과, heavy chain 72-75KD, light chain 30-40KD정도였다. 이상의 결과에서, 본 실험에서 사용된 IgY는 항원에 대한 특이성 및 생화학적 특성 등을 고려해 볼 때, 식품산업 소재, 의약품 소재, 연구용 kit와 진단용 kit 및 축산분야 등 여러 분야에 응용될 수 있으리라 기대된다.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.287-296
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• 2007

A Lactobacillus paraplantarum strain producing a bacteriocin was isolated from kimchi using the spot-on-the lawn method and named L. paraplantarum C7 [15]. The bacteriocin, paraplantaricin C7, was found to inhibit certain Lactobacillus strains, including L. plantarum, L. pentosus, and L. delbrueckii subsp. lactis. It also inhibited Enterococcus faecalis, yet did not inhibit most of the other LAB (lactic acid bacteria) tested. The maximum level of paraplantaricin C7 activity was observed under the culture conditions of $25^{\circ}C$ and a constant pH of 4.5. Paraplantaricin C7 retained 90% of its activity after 10 min of treatment at $100^{\circ}C$ and remained stable within a pH range of 2-8. Based on a culture supernatant, paraplantaricin C7 was purified by DEAE-Sephacel column chromatography and $C_{18}$ reverse-phase HPLC. SDS-PAGE and activity staining were then conducted using the purified paraplantaricin C7, and its molecular mass determined to be about 3,800 Da. The 28 N-terminal amino acids from the purified paraplantaricin C7 were determined, and the structural gene encoding paraplantaricin C7, ppnC7, was cloned by PCR using degenerate primers based on the N-terminal amino acid sequence. The nucleotide sequences for ppnC7 and other neighboring orfs exhibited a limited homology to the previously reported plantaricin operon genes. Paraplantaricin C7 is a novel type II bacteriocin containing a double glycine leader sequence.

• 분석과학
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• 제17권1호
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• pp.37-44
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• 2004

효모 Hansenula polymorpha 로부터 탄소원으로 0.5% 메탄올을 이용하여 알코올 산화효소를 대량 유도 발현하였다. 발현 유도된 Hansenula polymorpha 알코올 산화효소는 두 단계의 컬럼 크로마토그래피를 통하여 전기영동에서 단일밴드로 정제하였다. 정제한 효소는 주로 일차 지방족 알코올을 산화시키며, 에탄올에 대해 가장 높은 기질특이성을 보였다. 이 효소가 촉매하는 에탄올 산화반응의 최적 pH는 8.5 이였으며, 최적 온도는 $50^{\circ}C$를 나타내었다. 효소의 $T_m$ 값은 약 $52^{\circ}C$ 이었으며, $65^{\circ}C$에서도 완전히 불활성화 되지 않았다. 또한 효소는 변성제와 7주간의 비교적 장기간 보전에 대해서도 안정하였다. 이 효소는 알코올 측정을 위한 효소학적 방법 및 알코올과 알데히드의 공업적 생산에 이용될 수 있다.

• 대한미생물학회지
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• 제21권1호
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• pp.151-161
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• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• 한국식품과학회지
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• 제26권1호
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• pp.81-87
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• 1994

하늘타리박의 뿌리인 괄루근에서 분리 정제한 trypsin inhibitor는 TRTI-1과 TRTI-2 두 종류였으며 gel-filtration과 SDS-PAGE 전기영동에서 얻은 결과로부터 TRTI-1은 $4,000{\sim}5,000\;Da$의 분자량을 가진 monomer이며 TRTI-2는 $20,000{\sim}24,000\;Da$의 분자량을 가친 homodimer임을 알 수 있었다. 온도의 안정성에 있어서는 TRTI-1은 $100^{\circ}C$에서 2시간 이상 안정하였으며, TRTI-2는 $0{\sim}70^{\circ}C$의 온도에서는 안정하였으나 $80^{\circ}C$에서부터는 안정성이 떨어지면서 $100^{\circ}C$에서는 저해능이 완전히 소실되었다. Trypsin 활성에 대해서 TRTI-1, TRTI-2 및 상품화된 soybean BBI의 농도에 따른 저해능을 보면 TRTI-1, TRTI-2 및 soybean BBI의 각각의 농도가 $0.8{\mu}M,\;6{\mu}M,\;4{\mu}M$일 때 1mg/ml의 trypsin을 50% 저해하였으며, trypsin의 반응속도에 대한 TRTI의 저해 실험에서 TRTI-1와 TRTI-2 모두 trypsin의 가수분해를 경쟁적으로 저해하였으며 $K_{m}$값은 저해제가 없는 경우 $0.37\;{\mu}M$에 대해 각각 0.97, $0.63\;{\mu}M$이었다. 여러 protease에 대한 TRTI-1과 TRTI-2의 저해능 실험 결과 elastase, pepsin, Nagarase, papain, thermolysin, chymotrypsin, thrombin 및 collagenase 등은 저해하지 못하였고 trypsin만을 특이하게 저해하였다.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.244-250
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• 1990

토양으로부터 생전분을 분해하는 세균을 분리하였으며, Bacillus sp.로 동정하였다. 분리한 세균으로부터 생전분 분해효소의 생성을 위한 최적조건을 검토하였다. 세균은 탄소원으로 wheat 및 soluble starch를, 질소원으로 polypeptone을 사용했을 때 최대 효소생성을 얻을 수 있었다. 그리고 탄소원을 0.5, 질소원을 0.5 수준으로 사용했을 때 효소 생성을 극대화 하였다. 그리고 배지의 초기 pH를 6.5, 배양온도를 $35^{\circ}C$로 유지했을 때 효소생성이 높았다. Seepharose CL-6B 젤 여과 및 DEAE-Sephacel 이온교환수지를 사용하여 부분정제한 효소활성의 최적조건은 pH6.5, 온도 $70^{\circ}C$ 였다.