• 대한의생명과학회지
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• 제4권1호
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• pp.1-9
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• 1998

효모의 티올특이성 항산화단백과 아미노산 서열상 상동성을 보이는 50종류의 단백은 새로운 항산화 단백군을 형성하며 또한 병원성 미생물에도 널리 분포하고 있으나 이들 단백의 생화학적 및 생리적인 기능은 거의 알려져 있지 않은 실정이다. 본 연구는 병원성 미생물의 티올특이성 항산화단백의 기능에 관한 연구로서 Saccharomyces cerevisiae의 TSA 및 Salmonella typhimurium alkcyl hydroperoxide reductase의 AhpC subunit와 상동성을 나타내는 Corynebacterium diphtheriae의 DirA 유전자를 PCR 방법으로 클로닝하고 대장균에 발현시킨 후 정제하여 항산화 특성을 조사하였다. 정제된 DirA는 티올을 함유하는 금속촉매 산화계인 DTT/Fe$^{3+}$를 선택적으로 억제하였으며 티오레독신 의존성 과산화물 분해활성을 나타내었다. DTT/Fe$^{3+}$ 금속촉매 산화계에 의한 효소의 불활성화를 50% 억제 하는 DirA의 농도는 0.12 mg/ml로 효모 TSA 항산화활성의 약1/4 수준이었으며, 효모의 티 오레 독신계와 반응시켰을때 과산화물 분해활성은 0.02 unit/mg로서 효모 TSA의 티오레독신 의존성 과산화물 분해활성의 1/20수준이었다. 정제된 단백질을 이용하여 항체를 제조하였으며 이항체를 이용하여 Corynebacterium diphtheriae에서 발현됨을 확인하였다. 이러한 결과를 통하여 Corynebacterium diphtheriae의 병원성은 숙주세포의 방어기전인 백혈구에 의하여 생성되는 과산화수소 또는 다른 활성산소종을 제거하는 DirA작용과 연관이 있는 것으로 사료된다.

• 대한미생물학회지
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• 제8권1호
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• pp.13-17
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• 1973

To understand the characteristics of 29 toxigenic strains of Corynebacterium diphtheriae isolated in Seoul area, type classification, biochemical properties and antibiotic susceptibility pattern to 9 kinds of antibiotics were investigated. The results obtained were summerized as follows; I. Among the 29 strains, gravis type was the overwhelming majority(24 strains), followed by intermedius type(3 strains) and mitis type(2 strains). II. Fermentation of glucose, maltose, lactose, trehalose and mannitol, nitrate reduction and urease were tested. All strains fermented glucose, but not sucrose, lactose, mannitol and trehalose. 9 strains fermented maltose and 20 strains did not. Nitrate was reduced by 28 strains but not by one strain. In urease test one strain showed positive, 28 strains negative. III. Antibiotic susceptibility test to penicillin G, chloramphenical, kanamycin, lincomycin, streptomycin, terramycin, erythromycin and gentamycin were carried out. The MIC of erythromycin(0.025 ${\mu}g/ml$ 26 strains and 0.05 ${\mu}g/ml$ 3 strains) was the lowest, followed by ampicillin, lincomycin and penicillin G. Streptomycin showed the highest MIC.

• KSBB Journal
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• 제14권2호
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• pp.241-247
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• 1999

디프테리아는 Corynebacterium diphtheriae에 의해 발생되는 호흡기 질병으로 C. diphtheriae의 exo-toxin을 불활성화 시킨 toxoid 백신을 사용하여 예방해 왔다. 현재까지 국내에서는 정치배양 방법으로 디프테리아 toxin을 생산해 왔기 때문에 생산성과 품질에 한계가 있었으며, 이를 극복하기 위해 발효조를 이용한 발효조건 최적화에 대한 연구를 수행하였다. 디프테리아 toxin을 보다 효율적을 얻기 위한 배지로서 beef antigen이 함유되어 있지 않은 casein 유래의 NZ-Case를 선택하였다. 발효조에 의한 toxin 생성은 세포성장과 함께 증가하는 growh-associated form으로 나타났다. 최대의 세포성장과 toxin 생성은 초기 pH가 7.0인 배지에서 0.22vvm의 통기와 400rpm의 교반조건에서 얻을 수 있었다. 또한 최대의 toxin 생성을 위한 최적의 iron 이온의 농도는 0.3mg/L 이었으며, morgamcphospale의 첨가에 의한 calcium-phosphate 침전이 배지 내에 iron 이온의 농도조절을 위하여 요구되었다. 면역원성을 확인하기 위한 역가시험 결과 발효조 배양에서 얻은 toxoid는 4단위에서 모든 guinea-pigs가 생존하여 2단위인 정치배양 toxin에비해 월등히 우수한 것으로 판단되었다. 결국 발효조 배양으로 toxin을 생산할 경우 부작용이 적고 수율과 생산성 및 면역원성 이 우수한 toxid의 생산이 가능하였다.

• 약학회지
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• 제22권2호
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• pp.59-71
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• 1978

사람에게 병을 일으키는 수 많은 세균이 분비하는 다수의 외독소중, 이곳에서는 Corynebacterium diphtheriae의 외독소인 디프테리아 독소와 Vibrio cholerae가 분비하는 콜레라 장내 독소에 관해 주로 논하기로 하며, 디프테리아 독소와 생화학적 병인성 기전이 비슷한 Pseudomonas aeruginosa가 분비하는 pseudomnas외독소와 콜레라 장내독소와 병인성기전이 유사한 Escherichia coli의 장내독소에 관하여는 간략하게 언급하고져 한다.

• Molecules and Cells
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• 제38권8호
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• pp.715-722
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• 2015

In Gram-negative bacteria in the periplasmic space, the dimeric thioredoxin-fold protein DsbC isomerizes and reduces incorrect disulfide bonds of unfolded proteins, while the monomeric thioredoxin-fold protein DsbA introduces disulfide bonds in folding proteins. In the Gram-negative bacteria Salmonella enterica serovar Typhimurium, the reduced form of CueP scavenges the production of hydroxyl radicals in the copper-mediated Fenton reaction, and DsbC is responsible for keeping CueP in the reduced, active form. Some DsbA proteins fulfill the functions of DsbCs, which are not present in Gram-positive bacteria. In this study, we identified a DsbA homologous protein (CdDsbA) in the Corynebacterium diphtheriae genome and determined its crystal structure in the reduced condition at $1.5{\AA}$ resolution. CdDsbA consists of a monomeric thioredoxin-like fold with an inserted helical domain and unique N-terminal extended region. We confirmed that CdDsbA has disulfide bond somerase/reductase activity, and we present evidence that the N-terminal extended region is not required for this activity and folding of the core DsbA-like domain. Furthermore, we found that CdDsbA could reduce CueP from C. diphtheriae.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.11-15
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• 2004

본 연구에서는 C. diphtheriae toxin-A(DTA)를 합성하는 유전자를 tetracycline derivative인 doxycycline에 의해 발현이 유도되는 plasmid('Tet-on' system)에 삽입시켜, 이를 mouse ES cell에 도입시켰으며, 이렇게 제작된 mouse ES cell이 doxycycline의 처리 농도에 따라 mouse ES cell내의 DTA의 발현이 유도되어 이 결과 세포 사별(apoptosis)을 유발시키는 것을 MTT assay를 통해 확인하였다.

• 생체재료학회지
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• 제22권4호
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• pp.328-336
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• 2018

Background: Biogenic fabrication of silver nanoparticles from naturally occurring biomaterials provides an alternative, eco-friendly and cost-effective means of obtaining nanoparticles. It is a favourite pursuit of all scientists and has gained popularity because it prevents the environment from pollution. Our main objective to take up this project is to fabricate silver nanoparticles from lichen, Usnea longissima and explore their properties. In the present study, we report a benign method of biosynthesis of silver nanoparticles from aqueous-ethanolic extract of Usnea longissima and their characterization by ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses. Silver nanoparticles thus obtained were tested for antimicrobial activity against gram positive bacteria and gram negative bacteria. Results: Formation of silver nanoparticles was confirmed by the appearance of an absorption band at 400 nm in the UV-vis spectrum of the colloidal solution containing both the nanoparticles and U. longissima extract. Poly(ethylene glycol) coated silver nanoparticles showed additional absorption peaks at 424 and 450 nm. FTIR spectrum showed the involvement of amines, usnic acids, phenols, aldehydes and ketones in the reduction of silver ions to silver nanoparticles. Morphological studies showed three types of nanoparticles with an abundance of spherical shaped silver nanoparticles of 9.40-11.23 nm. Their average hydrodynamic diameter is 437.1 nm. Results of in vitro antibacterial activity of silver nanoparticles against Staphylococcus aureus, Streptococcus mutans, Streptococcus pyrogenes, Streptococcus viridans, Corynebacterium xerosis, Corynebacterium diphtheriae (gram positive bacteria) and Escherichia coli, Klebsiella pneuomoniae and Pseudomonas aeruginosa (gram negative bacteria) showed that it was effective against tested bacterial strains. However, S. mutans, C. diphtheriae and P. aeruginosa were resistant to silver nanoparticles. Conclusion: Lichens are rarely exploited for the fabrication of silver nanoparticles. In the present work the lichen acts as reducing as well as capping agent. They can therefore, be used to synthesize metal nanoparticles and their size may be controlled by monitoring the concentration of extract and metal ions. Since they are antibacterial they may be used for the treatment of bacterial infections in man and animal. They can also be used in purification of water, in soaps and medicine. Their sustained release may be achieved by coating them with a suitable polymer. Silver nanoparticles fabricated from edible U. longissima are free from toxic chemicals and therefore they can be safely used in medicine and medical devices. These silver nanoparticles were stable for weeks therefore they can be stored for longer duration of time without decomposition.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.622-627
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• 2002

Diphtheria toxin repressor (DtxR) binds to approximately 30 to 35-bp regions containing an interrupted 9-bp inverted repeat within a 19-bp core sequence. The core sequence is fairly conserved and critical for DtxR binding. The flanking regions that are consisted of 5 to 8 more of nucleotides from the core are also required for DtxR binding. The nucleotides in both flanking regions are A-T rich. To examine whether the A-T nucleotides in both flanking regions from the core have significant roles for DtxR binding, a DNA fragment was constructed based on the diphtheria tox promoter/operator, and DNA fragments with substitution of A and T nucleotides In the flanking regions to G and C were also constructed. To assess the effect of these substitutions on binding of DtxR and repressibility by DtxR, $\beta$-galactosidase activity from lacZ fused to the region was assessed. Gel mobility shift of the region by purified DtxR was also examined. The DNA fragments containing the mutations in the flanking regions still exhibited repression and mobility shift with DtxR. The core segment with the mutation is still, therefore, recognized by DtxR. Nonetheless, the results from the assays indicated that the substitution significantly decreased repression of the operator by DtxR in vivo under high-iron condition and decreased binding of DtxR to the operator. These results suggest that A and T nucleotides fur both flanking regions are preferred for the binding of DtxR.

• KSBB Journal
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• 제26권6호
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• pp.491-504
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• 2011

This review article provides an overview of the evolution of diphtheria vaccine, its value and its future. Diphtheria is an infectious illness caused by diphtheria toxin produced by pathogenic strains of Corynebacterium diphtheriae. It is characterized by a sore throat with membrane formation due to local tissue necrosis, which can lead to fatal airway obstruction; neural and cardiac damage are other common complications. Diphtheria vaccine was first brought to market in the 1920s, following the discovery that diphtheria toxin can be detoxified using formalin. However, conventional formalin-inactivated toxoid vaccines have some fundamental limitations. Innovative technologies and approaches with the potential to overcome these limitations are discussed in this paper. These include genetic inactivation of diphtheria toxoid, innovative vaccine delivery systems, new adjuvants (both TLR-independent and TLR-dependent adjuvants), and heat- and freeze-stable agents, as well as novel platforms for producing improved conventional vaccine, DNA vaccine, transcutaneous (microneedle-mediated) vaccine, oral vaccine and edible vaccine expressed in transgenic plants. These innovations target improvements in vaccine quality (efficacy, safety, stability and consistency), ease of use and/or thermal stability. Their successful development and use should help to increase global diphtheria vaccine coverage.

• 한국식품영양과학회지
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• 제45권7호
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• pp.1017-1025
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• 2016

기관지질환에 우수한 기능성을 가지고 있는 도라지는 수십종의 다양한 사포닌 종류를 함유하고 있다. 이러한 도라지를 젖산발효 시킬 경우 사포닌 조성의 변화와 기관지질환 유발 세균에 대한 항균 활성의 변화를 측정하였다. 도라지 발효를 위하여 사용된 젖산균은 Leuconostoc mesenteroides N12-4, Leuconostoc mesenteroides N58-5, Lactobacillus plantarum N76-10, Lactobacillus plantarum N56-12, Lactobacillus brevis N70-9 및 Lactobacillus brevis E3-8 등 6종이었다. 도라지 발효 시 젖산균 생육은 L. plantarum균이 가장 활발하였으며 pH 값도 가장 많이 내려가 발효 24시간째 pH는 3.73을 보였고 colony 수는 $10^7CFU/g$ 이상으로 증가하였다. 젖산발효 시간 동안 도라지 사포닌 9종에 대한 조성 변화는 사용된 도라지 시료에서 함량이 높았던 platycoside E, diapioplatycoside E, platycodin A, polygalacin D 등이 발효기간 중 일정량 감소하다가 발효 72시간 이후부터는 증가하는 경향이었고 platycodin D는 약간 증가하다가 72시간 이후부터는 오히려 감소하는 경향이었으며, 총사포닌 함량은 발효기간 동안 함량의 변화가 없었던 L. brevis E3-8균을 제외하고는 발효 72시간 이후 96시간째 증가하였다. 기관지질환 유발세균에 대한 항균 활성의 변화를 보기 위하여 사용된 세균은 Corynebacterium diphtheriae KCTC 3075, Klebsiella pneumoniae KCTC 2246, Staphylococcus aureus KCTC 1621 및 Streptococcus pyogenes ATCC 19615균 등 4종으로 각 균에 대한 항균 활성이 발효에 의하여 증대되는 젖산균은 L. plantarum균으로, 특히 L. plantarum N56-12균이 강한 항균 활성을 보여주었다. 이에 따라 각 기관지질환 유발세균에 대한 MIC를 조사한 결과 각 균에 대하여 도라지 무발효물은 200, 180, 210 및 90 mg/mL였고, L. plantarum N56-12균으로 발효된 도라지 상등액은 45, 10, 50 그리고 25 mg/mL였다.