• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.186-189
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• 2003

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 potent immunogen as well as major virulence factor. In order to express the recombinant urease in tobacco plants, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a plant expression vector. The recombinant vector was transformed to tobacco plants. The integration of the recombinant plasmids into tobacco chromosomal genome was verified by genomic PCR. Expression to mRNA was confirmed by Northern blot analysis, and expression to recombinant urease protein was observed by Western blot analysis. These results showed that the recombinant urease can be produced in tobacco plants and will be tested for immune response to use as an edible vaccine.

• 한국미생물·생명공학회지
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• 제21권3호
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• pp.288-292
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• 1993

An agar medium(HY) was developed to detect the urease-producing lactic acid bacteria. HY medium was prepared with the addition of tryptone, glucose and tween 80 to the supernatant of autoclaved skim milk and yeast extract mixture. There was no difference in eumeration of lactic acid bacteria between the HY and commercial media, such as M17, MRS and BCP agar. The urease activity of Streptococcus salivarius subsp. thermophilus was detected on the HY agar medium contained urea by the color change of bromocresol purple as the pH indicator, but not on the commerical agar media. Furthermore, it was succeeded to screen the urease activity of bacteria in skim milk used as a raw material in dairy product manufacture. Therefore, HY medium was proved to be suitable for the screening of urease-producing lactic acid bacteria.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.255-259
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• 1999

A 6.9-kb DNA fragment including the minimal Bacillus pasteurii urease gene cluster was subcloned into a high-copy-number plasmid vector, pUC19, and the recombinant B. pasteurii urease was overexpressed in Escherichia coli. The recombinant urease was purified 25.9-fold by using combinations of anion-exchange and gel-filtration chromatography followed by Mono-Q chromatography on a FPLC. N-terminal peptide sequencing analyses revealed that two distinct smaller peptide bands resolved on a 10-18％ gradient SDS-PAGE corresponded to UreA and UreB peptides, respectively. It was also shown that the ureB gene was translated from a GUG codon and the first methionine residue was post-translationally cleaved off. The native molecular weight of the recombinant urease was 176,000 and 2 nickel atoms were present per catalytic unit. pH stability studies of the purified enzyme showed that the recombinant Bacillus pasteurii urease is stable in alkaline pH range, which is similar to the enzyme of the evolutionarily related bacterium, Sporosarcina ureae.

• Journal of Life Science
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• 제9권1호
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• pp.5-8
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• 1999

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 a potent immunogen. Deletion mutageneses were performed in the H. pylori urease accessory genes by using combinations of restriction enzymes and other DNA modifying enzymes in order to assess the function of these accessory gene products in the expression of the active urease. Selective disruptions in the accessory gene regions resulted in complete abolishment of the urease activity, which is consistent with other bacterial ureases. Interestingly, deletions in ureE-containing regions caused reduced expression of the structural enzyme subunits.

• KSBB Journal
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• 제19권5호
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• pp.348-351
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• 2004

Ethanol ($70\%$) extract of Caesalpinia sappan L. and Forsythiae suspensa Vahl. showed $84\%$ and $72\%$ of anti-urease activity against Helicobacter pylori, respectively. Among the fraction of Artemisia asiatica Nakai extract using methanol ($80\%$), water, ethyl acetate and butanol ethyl acetate fraction showed $90\%$ of the anti-urease activity.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.332.1-332.1
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• 2002

Streptococcus vestibularis is a urease-producing oral bacterium. frequently isolated from vestibular mucosa of human oral cavity. Ureolysis by S. vestibularis and other ureolytic oral bacteria is believed to be crucially involved in oral microbial ecology and oral health. Genomic library of the S. vestibularis ATCC49124 was constructed in an E. coli plasmid vector and the urease-positive transformants harboring the urease gene cluster were isolated on Christensen-urea agar plates. The minimal DNA region required for the urease activity was located on a 5.6 kb DNA fragment. (omitted)

• 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.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.30-36
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• 1997

To genetically breed powerful multifunctional antagonistic bacteria, the urease gene of alkalophilic Bacillus pasteurii was transferred into Bacillus subtilis YB-70 which had been selected as a powerful biocontrol agent against root-rotting fungus Fusarium solani. Urease gene was inserted into the HindIII site of pGB215-110 and designated pGU266. The plasmid pGU266 containing urease gene was introduced into the B. subtilis YB-70 by alkali cation transformation system and the urease gene was very stably expressed in the transformant of B. subtilis YB-70(pGU266). The optimal conditions for the transfomation were also evaluated. From the in vitro antibiosis tests against F. solani, the antifungal activity of B. subtilis YB-70 containing urease gene was much efficient than that of the non-transformed strain. Genetic improvement of B. subtilis YB-70 by transfer of urease gene for the efficient control seemed to be responsible for enhanced plant growth and biocontrol efficacy by combining its astibiotic action and ammonia producing ability.

• Asian-Australasian Journal of Animal Sciences
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• 제14권9호
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• pp.1216-1220
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• 2001

Effect of hydroquinone (HQ) on rumen urease activity was studied. Hydroquinone at concentrations of 0.01 ppm, 0.1 ppm, 1 ppm, and 10 ppm inhibited urease activity of intact rumen microbes in vitro by 25%, 34%, 55% and 64% respectively. In the presence of low concentrations of $\beta$-mercaptoethanol, rumen urease could be solubilized and partially purified. The Km for the enzyme was $2{\times}10^{-3}$ M with Vmax of $319.4{\mu}moles/mg$ min. The kinetics of inhibition with partially purified rumen urease was investigated. The result showed that the inhibitory effect was not eliminated by increasing urea concentrations indicating a noncompetitive effect in nature with an inhibition constant $1.2{\times}10^{-5}$ M. Hydroquinone at the concentration of 10 ppm produced 64% urease inhibition, did not affect ruminal total dehydrogenase and proteolytic enzyme (p>0.05), but increased cellulase activity by 28% (p<0.05) in vitro. These results indicated that hydroquinone was a effective inhibitor of rumen urease and could effectively delay urea hydrolysis without a negative effect. The inhibitor appeared to offer a potential to improve nitrogen utilization by ruminants fed diets containing urea.

• 한국미생물·생명공학회지
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• 제13권3호
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• pp.297-302
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• 1985

미생물중 urease생성능이 아주 강한 B. pasteurii의 Hind III partial digest 된 chromosomal DNA를 E. coli-B. subtilis bifunctional plasmid vector pGR 71으로 E. coli RR1 균주에 cloning 하므로써 그 urease gene을 expression시킬 수 있었다. 그러나 B. subtilis에서는 insertion DNA fragment의 deletion으로 expression되지 않았다. Cloning된 E.coli RR1 균주로부터 분리 정제한 urease gene함유 Plasmid(pGU66)의 restriction map을 작성하여 본 결과 7.1 Mdal의 insertion fragment가 삽입된 12.6Mdal의 plasmid에 Hind III, Bgl II, Xba I, Sal I등 몇 개의 cleavage site 위치를 찾을 수 있었다. Cloning된 E. coli의 urease는 periplasmic space에 많은 비율로 축적되며, 그 효소학적 성질은 donor인 B.pasteurii의 그것과 매우 유사하였다.