• BMB Reports
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• 제31권3호
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• pp.240-244
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• 1998

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a major virulence factor and in a potent immunogen. In order to express the recombinant urease at a higher level, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a high copy-number vector. The recombinant H. pylori urease expressed in an E. coli strain that was grown in a rich medium supplemented with added nickel was purified to near homogeneity by using DEAE-Sepharose, Superdex HR200, and Mono-Q (FPLC) columns and the purified enzyme possessed the specific activity of 1255 U/mg. Polyclonal antibodies raised against the purified recombinant H. pylori urease were shown to be very specific when subjected to Western blot analysis, in which crude extracts from the H. pylori ATCC strain and the recombinant E. coli strains expressing various bacterial ureases were exnmined for cross-reactivity.

• 생명과학회지
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• 제13권1호
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• pp.67-72
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• 2003

위염, 위궤양 및 위암의 원인 균인 Helicobacter pylori 가균체 표면에 다량 함유하며 주된 생존 인자이며 병원성 인자인 urease를 대장균에서 발현시키고 이 효소에 대한 항체 또는 기질과의 특이 상호 작용을 이용하여 두 단계의 간편한 방법에 의하여 정제하였다. 우선 anti-H. pylori Urease IgG-Sepharose column과 urea-Sepharose column을 각각 제조하고 DEAE-Sepharose 음이온 교환수지를 통하여 1차 정제한 시료를 각각 적용하고 제반 조건에서 용출시켰다. Anti-H. pylori urease IgG-Sepharose column의 경우에는 urease 시료가 너무 강력하게 결합함으로써 극단적인 pH조건에서만 용출이 가능함이 관찰되었으므로, 100 mM 탄산 완충액(pH 10.5)으로 최종 용출하였을 때 비교적 순수한 효소를 얻었으나, 비활성이 다소 감소된 것으로 나타났다. 한편, urea-Sepharose에 적용시킨 시료는 100 mM urea-HEB 완충액(pH 7.5)으로 비교적 용이하게 용출되어 비교적 높은 순도와 비활성의 urease 효소를 얻을 수 있었으나 이 경우에는 urease의 smaller subunit인 UreA peptide band의 강도가 다소 감소한 것이 관찰되었다.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.317-325
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• 2001

For heuristic purposes, the relative ratio of urease contents inside and outside cells was surveyed using nine ureB+ strains of Helicobacter pylori. the ratio of the enzyme specific activity appeared to vary greatly between the various H. pylori strains, ranging from 0.5 to 2.5. Besides the above compartment, urease was also richly found in the membrane fraction, especially in either peripheral or integral form. The urease distribution across the H. pylori membrane was significantly influenced by the ambient pH; the specific activity of external urease was highest at pH 5.5 with a narrow plateau, whereas the internal specific activity was highest within a pH range of 4.5 to 6.5 with a broad plateau. These finding strongly suggest that H. pylori urease is secretory and responded to the external pH. However, at pH 4.0 or below, no urease activity was detected in either the internal or external compartment, although an increase in the color development with 2,4,6-trinitrobenzene sulfonate (TNBS) was observed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these phenomena may be related to a specific proteolysis in certain proteins, including urease or ${\gamma}$-glutamyl transpeptidase. Interestingly, the effect of ammonium ions n alleviating the enzyme inactivation inside the H. pylori cells was remarkably similar to that of D-glucose. In addition, it would appear that the cation acted as a surrogate of not only $Na^+$ but also $K^+$ thereby increasing the H. pylori P-type ATPase activity. This is of great interest, as it implies that the urease action in H. pylori is indispensible at any locus.

• 식물조직배양학회지
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• 제27권3호
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• pp.239-243
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• 2000

위염과 위궤양을 일으키는 Helicobacter pylori는 그 감염 환자에서 강한 항체형성을 유도하는 urease를 생산한다. 식물체를 이용하여 H. pylori에 대한 식용백신 모델을 제조하기 위하여 H. pylori의 urease 유전자를 지니고 있는 pH808 plasmid로부터 750bp의 ureA DNA를 PCR에 의해서 증폭한 후 이를 담배식물에서 발현이 되도록 조작하였다. 재분화된 형질전환 식물체로부터 ureA 유전자의 도입과 mRNA발현 및 단백질합성을 분석하였다. CaMV 35S promoter에 의한 ureA 유전자의 발현은 SDS polyacrylamide 전기영동 및 immunoblot실험에서 박테리아로부터의 재조합 단백질과 같은 크기의 30 kDA UreA 단백질이 생산되었음을 확인할 수 있었다.

• 생명과학회지
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• 제18권2호
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• pp.241-248
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• 2008

축산물을 이용하여 생산된 특이항체는 세균성감염에 의한 설사병 치료와 충치예방에 효과가 있고, 특히 계란을 이용한 IgY (Immunoglobulin Yolk)는 비교적 산과 열에 안정하다는 실험결과가 보고되어[22] 있다. 식품분야에 특이항체를 식품소재로 산업화에 활용한 빈도는 아직 미미한 상태에 있으나, 최근 면역학, 단백질공학, 생명공학 등의 발전과 기술 향상으로 식품 소제로써의 활용성이 점차 높아질 것으로 기대된다. 본 연구에서는 H. pylori의 감염을 예방하고 치료보조제로 사용할 목적으로 포유동물을 통한 피동면역용 항체를 생산하고자 하였다. H. pylori로부터 항원을 분리하고, 분리된 항원에 대한 항체생산 및 H. pylori의 응집정도를 알아보았다. H. pylori로부터 분리된 주요 항원 단백질은 WC, OMP, crude urease, LPS 각각 12개, 7개, 3개, 1개 종류의 band를 확인할 수 있었다. 분리된 항원의 IgG 항체 생성은 동일한 항원농도인 $20{\mu}g/100{\mu}l$에서 각각 WC (L) $77.9{\pm}6.4{\mu}g/ml$, OMP $84.9{\pm}6.4{\mu}g/ml$, crude urease $123.8{\pm}2.9{\mu}g/ml$로 crude urease 항원이 가장 많은 것으로 나타났다. 그리고 IgA 항체 생성은 WC (L) $2.5{\pm}0.32{\mu}g/ml$, OMP $2.0{\pm}0.43{\mu}g/ml$, crude urease $1.3{\pm}0.25{\mu}g/ml$로 IgA 항체 생성은 WC (L) 항원이 가장 많은 것으로 나타났다 Western blotting을 통하여 항원 단백질의 면역원성 알아본 결과 WC 10종류, OMP 6종류, crude urease 3종류의 주요 항원성 물질을 확인할 수 있었다. 항체의 H. pylori에 대한 응집정도를 나타내는 응집가는 anti-WC (H), anti-WC (L), anti-OMP, anti-crude urease 항혈청에서 각각 $2^5,\;2^5,\;2^6\;and\;2^7$으로 나타났으며, 상대적으로 anti-crude urease 항혈청이 가장 높은 응집가를 나타내었다. 각 항원에 의해 생성된 항혈청의 urease활성 억제에 대한 흡광도(OD=550 nm)는 WC (H) $0.14{\pm}0.01$, WC (L) $0.16{\pm}0.01$, OMP $0.18{\pm}0.03$, Urease $0.18{\pm}0.04$로 대조구 $0.26{\pm}0.02$와 비교할 때 유의적인 억제효과가 있는 것으로 나타났다. 이상의 결과를 종합해 볼 때 H. pylori 항원의 분리와 분리된 항원의 항체 생성능, H. pylori의 응집가, urease 활성억제측면에서 WC 및 crude urease항원 모두 높은 항체 역가를 나타내었다.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.275-279
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• 1997

Helicobacter pylori (H. pylorl) infection is now established as the major pathogenic factor in chronic gastritis and peptic ulcer disease. in addition, there is accumulating evidence that H. pylori plays an important role in the process of gastric carcinogenesis. On the other hand, oriental traditional medicines have been used for stomach disease for thousands of years. In the present study, methanol extract from the stem bark of Magnolia sieboldii (M. sieboldii) and its components were investigated on their inhibitory effects against urease activity and growth of H. pylori in vitro. The methanol extract of M. sieboldii significantly inhibited the growth of H. pylori ATCC 43504 at 5 mg/ml. From the further fractionation, the chloroform fraction inhibited the bacterial growth dose-dependently. Among four fractions separated from the chloroform fraction by silica gel column chromatography, MS-C-2 was the most potent. Costunolide was isolated from the MS-C-2 subtraction by preparative TLC and recrystallization using n-hexane. Anti-H. pylori effect of costunolide was investigated using one commercial strain (H. pylori ATCC 43504) and three clinical strains (H. pylon 4, 43, 82548). Costunolide exhibited potent anti-H. pylori activity, and the MIC was around $100-200{\mu}g/ml$. However, costunolide had no inhibitory effect of H. pylori urease activity at the concentration used for the growth inhibition assay. From these results, we conclude that costunolide inhibits the, growth of H. pylori by the independent manner of H. pylori urease inhibition.

• 한국식품과학회지
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• 제38권1호
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• pp.93-98
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• 2006

본 연구는 H. pylori를 산란계에 면역화하여 얻은 항-H. pylori 난황항체 분말의 H. pylori에 대한 억제효과를 알아보기 위하여 실시하였다. 마우스의 종에 따라서 H. pylori에 대한 감수성의 차이가 있다고 보고된 바 있다(25). Richard 등의 연구결과에 의하면 C57BL/6 mice는 H. pylori에 대하여 약 70%의 감수성을 가진 것으로 보고하였다(26). 이번 실험에서는 7주째의 urease test 결과 항-H. pylori 난황항체 분말을 급이한 군에서 33%의 낮은 양성율을 보였고, 흡광도 측정결과도 유의적으로 감소하였다. 조직학적 검사에서 접종대조군의 위조직은 염증성 세포의 집적 등 특이적인 염증성 변화를 동반하였지만, 항-H. pylori 난황항체 분말을 급이한 군에서는 특이적 변화를 관찰할 수 없었다. H. pylori의 제균효과를 확인하는 방법중 하나인 ureA 유전자 확인결과, 항-H. pylori 난황항체 분말을 급이한 군에서는 3주째보다 7주째 많이 감소하였다. 항-H. pylori 난황항체 분말의 급이시기는 감염전이나 감염후에 큰 차이를 보이지 않았으며, 급이수준은 5%보다는 10% 첨가수준이 약간 높게 나타났다. 이 연구결과로 동물시험에서 항-H. pylori 난황항체 분말이 H. pylori 억제 효과가 있음이 확인되었다.

• 대한미생물학회지
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• 제34권6호
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• pp.533-542
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• 1999

H. pylori produces urease abundantly amounting to 6% of total protein of bacterial mass. Urease genes are composed of a cluster of 9 genes of ureC, ureD, ureA, ureB, ureI, ureE, ureF, ureG, ureH. Production of H. pylori urease in E. coli was studied with genetic cotransformation. Structural genes ureA and ureB produce urease apoprotein in E. coli but the apoprotein has no enzymatic activity. ureC and ureD do not affect urease production nor enzyme activity ureF, ureG, and ureH are essential to produce the catalytically active H. pylori urease of structural genes (ureA and ureB) in E.coli. The kinetics of activation of H. pylori urease apoprotein were examined to understand the production of active H. pylori urease. Activation of H. pylori urease apoprotein, pH dependency, reversibility of $CO_2$ binding, irreversibility of $CO_2$ and $Ni^{2+}$ incorporation, and $CO_2$ dependency of initial rate of urease activity have been observed in vitro. The intrinsic reactivity (ko) for carbamylation of urease apoprotein co expressed with accessory genes was 17-fold greater than that of urease apoprotein expressed without accessory genes. It is concluded that accessory genes function in maximizing the carbamylating deprotonated ${\varepsilon}$-amino group of Lys 219 of urease B subunit and metallocenter of urease apoprotein is supposed to be assembled by reaction of a deprotonated protein side chain with an activating $CO_2$ molecule to generate ligands that facilitate productive nickel binding.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.865-872
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• 2000

Helocobacter phylori is the major cause of gastritis, peptic ulcer, and a principal risk factor for gastric cancer. As the firs step towards a vaccine against H. pylori infection, Hy.pylori urease was expressed and purified as a recombinant apoenzyme (rUrease) in E. coli. In order to develop an effective immunization protocol using rUrease, the host immune responses were evaluated after the oral immunization of mice with rUrease preparations plus cholera toxin relative to various conditions, such as the physical nature of the antigen, the frequency of the booster immunization, the dose of the antigen, and the route of administration. The protective efficacy was assessed using a quantitative culture following an H. pylori SS1 challenge. It was demonstrated that rUrease, due to its particulated nature, was more superior than the UreB subunit as a vaccine antigen. The oral immunization of rUrease elicited significant systemic and secretory antibody responses, and activated predominantly Th2-type cellular responses. The bacterial colonization was significantly reduced (~100-fold) in those mice immunized with three or four weekly oran doses of rUrease plus cholera toxin (p<0.05), when compared to the non-immunized/challenged controls. The protection correlated well with the elicited secretory IgA level against rUrease, and these secretory antibody responses were highly dependent on the frequency of the booster immunization, yet unaffected by the dose of the antigen (25-200$\mu\textrm{g}$). These results demonstrate the remarkable potential of rUrease as a vaccine antigen, thereby strengthening the possibility of developing an H. pylori vaccine for humans.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.264-265
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• 2000

Helicobacter pylori(H. pylori) is the causative agent of chronic gastritis and the single most important factor in peptic ulcer disease, however, the pathogenetic mechanisms underlying H, pylori infection are not well understood. Futhermore, there is a strong association between H. pylori infection and gastric cancer. Various diagnostic methods for detecting H. pylori infection are available. These can be divided into invasive methods, requiring endoscopy, and non-invasive tests, mainly 13C-urea breath tests and serologic detection of antibodies. Rapid urease test is the most recommendable endoscopic test for the diagnosis of H. pylori infection, presently. CLO test kit is the represent of rapid urease test kits. The principles of CLO test kit is that hydrolysis of urea by urease Is detected by a dye indicators showing a color change. Our device is used same principle but we improved the reaction time is more faster and positive color change is more distinctive from the color of the negative specimen. So, this kit is more reliable because it response faster and accuracy.