• BMB Reports
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• 제37권5호
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• pp.597-602
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• 2004

N-terminal His-tagged recombinant $\beta$-1,4-galactosyltransferase from Neisseria meningitidis was expressed and purified to homogeneity by column chromatography using Ni-NTA resin. Mutations were introduced to investigate the roles of, Ser68, His69, Glu88, Asp90, and Tyr156, which are components of a highly conserved region in recombinant $\beta$-1,4 galactosyltransferase. Also, the functions of three other cysteine residues, Cys65, Cys139, and Cys205, were investigated using site-directed mutagenesis to determine the location of the disulfide bond and the role of the sulfhydryl groups. Purified mutant galactosyltransferases, His69Phe, Glu88Gln and Asp90Asn completely shut down wild-type galactosyltransferase activity (1-3%). Also, Ser68Ala showed much lower activity than wild-type galactosyltransferase (19%). However, only the substitution of Tyr156Phe resulted in a slight reduction in galactosyltransferase activity (90%). The enzyme was found to remain active when the cysteine residues at positions 139 and 205 were replaced separately with serine. However, enzyme reactivity was found to be markedly reduced when Cys65 was replaced with serine (27%). These results indicate that conserved amino acids such as Cys65, Ser68, His69, Glu88, and Asp90 may be involved in the binding of substrates or in the catalysis of the galactosyltransferase reaction.

• Journal of Microbiology
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• 제44권6호
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• pp.685-688
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• 2006

The aim of this study was to characterize the molecular features of serogroup C Neisseria meningitidis strains circulating in Beijing, China. Twenty out of 23 strains belonged to ST 4821. The causative serosubtype for meningococcal meningitis was P1.12-1,16-8. All of the strains expressed class 3 PorB protein. Among the five pulsed-field gel electrophoresis patterns observed, pattern III predominated.

• BMB Reports
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• 제35권3호
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• pp.330-336
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• 2002

The lgtB genes that encode $\beta$-1,4-galactosyltransferases from Neisseria meningitidis ATCC 13102 and gonorrhoeae ATCC 31151 were isolated by a polymerase chain reaction using the pfu DNA polymerase. They were expressed under the control of lac and T7 promoters in Escherichia coli M15 and BL21 (DE3). Although the genes were efficiently expressed in E. coli M15 at $37^{\circ}C$ (33 kDa), most of the $\beta$-1,4-galactosyltransferases that were produced were insoluble and proteolysed into enzymatically inactive polypeptides that lacked C-terminal residues (29.5 kDa and 28 kDa) during the purification steps. When the temperature of the cell growth was lowered to $25^{\circ}C$, however, the solubility of the $\beta$-1,4-galactosyltransferases increased substantially. A stable N-terminal his-tagged recombinant enzyme preparation could be achieved with E. coli BL21 (DE3) that expressed lgtB. Therefore, the cloned $\beta$-1,4-galactosyltransferases were expressed under the control of the T7 promoter in E. coli BL21 (DE3), mostly to the soluble form at $25^{\circ}C$. The proteins were easily purified to homogeneity by column chromatography using Ni-NTA resin, and were found to be active. The galactosyltransferases exhibited pH optimum at 6.5-7.0, and had an essential requirement for the $Mn^{+2}$ ions for its action. The $Mg^{+2}$ and $Ca{+2}$ ions showed about half of the galactosyltransferase activities with the $Mn^{+2}$ ion. In the presence of the $Fe^{+2}$ ion, partial activation was observed with the $\beta$-1,4-galactosyltransferase from N. meningitidis(64% of the enzyme activity with the $Mn^{+2}$$Ni^{+2}$, $Zn^{+2}$, and $Cu^{+2}$ ions could not activate the $\beta$-1,4-galactosyltransferase activity. The inhibited enzyme activity with the $Ni^{+2}$ ion was partially recovered with the $Mn^{+2}$$Fe^{+2}$, $Zn^{+2}$, and $Cu^{+2}$ ions, the $Mn^{+2}$$\beta$-1,4-galactosyltransferase activity was 1.5-fold stimulated with the non-ionic detergent Triton X-100 (0.1-5%).

• Journal of Microbiology
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• 제44권4호
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• pp.457-460
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• 2006

A suspicious meningococcal meningitis death case was reported to the Beijing CDC. The blood specimen was analyzed via multi-PCR and MLST. 6 isolates from close contacts were analyzed via PFGE and MLST. According to the results of the above analyses, the cause of this case was identified as a serogroup A Neisseria meningitidis, which, in terms of sequence typing, belonged the ST7 group.

• Pediatric Infection and Vaccine
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• 제25권3호
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• pp.165-169
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• 2018

수막구균 감염은 신생아에서 높은 사망률을 보이지만 매우 드물고, 단체 생활하는 연장아나 청소년에서 더 흔하다고 알려져 있다. 이 증례에서 소개된 생후 16일 신생아는 수막구균 B 혈청군 패혈증과 수막염이 진단되었지만 조기 항생제 치료를 통해 합병증 없이 건강하게 퇴원하였다. 이 증례 보고의 목적은 신생아에서 수막구균 감염의 발생률과 중요성을 상기시키고 노출된 가족들과 의료진에 대한 조사와 예방 요법의 필요성을 강조하기 위함이다. 한국에서는 많은 신생아가 출생 후 산후조리원 시설에서 지내내므로 감염 발생과 전파에 단체 생활이 영향을 미칠 수도 있음을 생각해 볼 필요가 있다. 질병의 조기 발견, 격리, 그리고 경험적 치료가 치명적인 질병의 전파를 예방하기 위해 매우 중요하다.

• 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.147-148
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• 2002

Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis are encapsulated bacteria which encounter the respiratory mucosa and cause nasopharyngeal carriage that may lead to mild mucosal infections or severe invasive disease. (omitted)

• Pediatric Infection and Vaccine
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• 제11권1호
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• pp.126-130
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• 2004

본 저자들은 A군 연쇄구균 감염 후 급성 사구체신염과 동반된 수막구균감염증(수막구균 뇌수막염, 수막구균혈증)에 걸린 7세 남아를 경험하였는데 A군 연쇄구균 감염 후 급성 사구체 신염으로 인해서 C3가 감소하여 수막구균감염증에 감염이 되었는지, 역으로 가능성은 떨어지지만 수막구균감염증의 결과로 C3가 감소하였고 사구체신염이 생긴 것인지 전후 관계가 확실하지 않은 증례를 문헌고찰과 함께 보고하는 바이다.

• Pediatric Infection and Vaccine
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• 제13권2호
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• pp.124-129
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• 2006

목 적 : 1996년부터 2005년까지 단일기관에서 발생한 세균성 수막염의 주요 원인균의 연령별 분포를 조사하였다. 방 법 : 1996년 1월부터 2005년 12월까지 세브란스병원 소아과에 입원하여 세균성 수막염이나 신생아 수막염으로 진단받은 환아들 중 뇌척수액 배양검사 및 라텍스응집반응검사에서 원인균이 확인된 증례들의 의무기록을 후향적으로 조사하였다. 결 과 : 원인균이 확인된 46례 중 신생아 수막염은 미숙아 4례를 포함하여 27례였고 신생아기 이후의 세균성 수막염은 19례였다. 신생아 수막염 환아 중 원인균이 혈액배양검사에서도 동정된 경우는 모두 15례(55.6%)였다. 신생아 수막염의 가장 흔한 원인균은 B군 연쇄상 구균이었다(44.4%). 또한 B군 연쇄상 구균에 의한 수막염의 75.0%가 지발형 감염이었다. 신생아기 이후의 세균성 수막염 환아들의 84.2%가 5세 미만에서 발생하여, 이들의 연령 중앙값은 23개월이었다. 신생아기 이후의 세균성 수막염의 원인균으로는 폐구균 8례(42.1%), 인플루엔자균 8례, 수막구균 3례 등이 있었으며, 이 중 인플루엔자균는 2001년 이후 최근 5년간 검출되지 않았다. 결 론 : 신생아 수막염의 가장 흔한 원인균은 B군 연쇄상 구균이고 신생아기 이후에는 폐구균과 인플루엔자균이 세균성 수막염의 가장 흔한 원인균이었다. 이 중 단백결합 백신의 도입으로 인플루엔자균에 의한 세균성 수막염은 감소되는 경향을 보였다.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.621-629
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• 2022

Bacterial outer membrane vesicles (OMVs) typically contain multiple immunogenic molecules that include antigenic proteins, making them good candidates for vaccine development. In animal models, vaccination with OMVs has been shown to confer protective immune responses against many bacterial diseases. It is possible to genetically introduce heterologous protein antigens to the bacterial host that can then be produced and relocated to reside within the OMVs by means of the host secretion mechanisms. Accordingly, in this study we sought to develop a novel platform for recombinant OMV (rOMV) production in the widely used bacterial expression host species, Escherichia coli. Three different lipoprotein signal peptides including their Lol signals and tether sequences-from Neisseria meningitidis fHbp, Leptospira interrogans LipL32, and Campylobactor jejuni JlpA-were combined upstream to the GFPmut2 model protein, resulting in three recombinant plasmids. Pilot expression studies showed that the fusion between fHbp and GFPmut2 was the only promising construct; therefore, we used this construct for large-scale expression. After inducing recombinant protein expression, the nanovesicles were harvested from cell-free culture media by ultrafiltration and ultracentrifugation. Transmission electron microscopy demonstrated that the obtained rOMVs were closed, circular single-membrane particles, 20-200 nm in size. Western blotting confirmed the presence of GFPmut2 in the isolated vesicles. Collectively, although this is a non-optimized, proof-of-concept study, it demonstrates the feasibility of this platform in directing target proteins into the vesicles for OMV-based vaccine development.

• Pediatric Infection and Vaccine
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• 제11권2호
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• pp.212-215
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• 2004

보체계는 우리 몸에서 감염에 대한 초기 방어를 담당하는데 그중 후기 보체 성분의 결핍시 수막구균의 감염에 쉽게 노출된다. 특히 재발 감염된 수막구균 혈증 환자에서 보체계의 검사가 반드시 필요할 것으로 생각되는 바이다. 저자들은 재발성 수막구균 혈증으로 치료받은 환자에서 C7 결핍증을 경험하였기에 이를 보고하는 바이다.