• 한국광학회지
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• 제13권1호
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• pp.84-87
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• 2002

SOA (Semiconductor Optical Amplifier)의 inverter 원리를 응용하여 RZ 형식의 전광 XOR논리소자가 5 Gb/s 속도에서 처음으론 구현되었다. 먼저 Boolean AB와 Boolean AB가 실험적으로 구현되었으며 전광 XOR논리소자를 만들기 위해서 AB와 AB를 합하여 XOR의 Boolean 값인 AB+AB의 특성이 얻어졌다.

• 한국식품과학회지
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• 제30권3호
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• pp.709-716
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• 1998

양송이의 알칼리 추출물에서 면역계의 주요인자인보체계와 macrophage를 활성화시키는 다당들을 분리, 정제하고 구조적 특성을 비교하였다. AB-20-IVa-2는 항보체 활성과 macrophage 활성능을 동시에 나타내는 단백다당으로 주요 구성당은 glucose > galactose > mannose 순으로 함유되어 있고 주요 구성아미노산은 phenylalanine (34.72%)과 valine (27.84%)이었다. AB-20-Ia와 AB-20-IIa-2a는 macrophage 활성을 갖고 있는 순수다당으로 AB-20-Ia의 주요 구성당은 glucose > xylose > mannose이고 AB-20-IIa-2a는 xylose > glucose > mannose이었다. AB-20-Ia, AB-20-IIa-2a, AB-20-IVa-2의 분자량은 각각 84만, 75만, 65만 정도로 추정되었다. AB-20-Ia, AB-20-IIa-2a, AB-20-IVa-2의 구조적 특성을 비교하기 위하여 NMR 분석, methyl화 분석을 통해 anomer 배위 양식과 당쇄 결합 양식을 조사하였다. AB-20-Ia는 ${\beta}-anomer$ 형태로 존재하는데 비해서 AB-20-IIa-2a는 ${\alpha}-$와 ${\beta}-anomer$ 모두 확인되었으며 ${\beta}-$의 비율이 좀 더 높았다. 또, AB-20-Ia와 AB-20-IIa-2a 모두 구성당 잔기에 acetyl기가 존재하였으며 특히, macrophage 활성능이 더 강한 AB-20-IIa-2a에 더 높은 비율로 함유되어 있었다. 이 정제 다당들의 당쇄 결합양식은 AB-20-Ia는 주로 ${\beta}-1,6-linked\;glucofuranosyl$ 잔기가 주쇄를 구성하고 있고, AB-20-IIa-2a는 1,6-linked glucopyranosyl 잔기가 주쇄를 이루고 여기에 측쇄들이 1,4 결합으로 연결된 다당으로 추정되었다. 또, AB-20-IVa-2는 1,2-linked xylofuranosyl 잔기와 1,6-linked glucopyranosyl 잔기가 주쇄를 이루고 이 xylofuranosyl 잔기에 측쇄들이 1,3 결합으로 연결된 다당으로 추정되었다.

• Applied Biological Chemistry
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• 제41권1호
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• pp.60-66
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• 1998

10종의 식용 버섯 자실체에 대한 항보체 활성 검색에서 가장 높은 활성을 나타낸 양송이버섯 자실체를 대상으로 항보체 활성물질의 추출조건을 조사하였다. 최적조건으로서 5% urea가 함유된 0.1 N NaOH 용액으로 $65^{\circ}C$에서 2시간동안 양송이버섯 자실체를 추출한 후 methanol 가용획분이 제거된 조다당 획분 AB-0를 얻었다. AB-0는 1 mg/ml에서 90% 이상의 높은 항보체활성을 나타내었으며 마우스에 이식된 sarcoma-180에 대하여 74%의 저지효과를 보였다. AB-0를 acetone 농도에 따른 침전 분획을 실시하여 AB-20, AB-40, AB-60, AB-80, AB-A의 5개의 획분을 얻었다. 이중 가장 높은 항보체활성과 수율을 나타낸 AB-20 획분은 탄수화물 39%, 단백질 46%를 함유하였으며, 구성당은 glucose, arabinose, xylose, galactose, mannose가 6.49 : 1.98 : 1.24 : 1.00 : 0.71의 비율로 존재하였고 구성아미노산은 isoleucine(12.60%), glutamic acid+glutamine(12.45%), valine(11.79%), alanine(11.46%), leucine(10.19%)와 aspartic acid, asparagine(10.56%) 등 이었다. Pronase 처리한 AB-20에서는 78.5%의 항보체활성을 나타내고 대조군에 비해 14.5% 감소하였으나, AB-20의 periodate 산화물에서는 활성이 42.6%로 50% 이상 크게 감소하였다. 따라서 양송이 버섯의 알칼리 추출물중 가장 강한 활성을 보인 AB-20의 주요 활성부위는 다당류이며 단백질도 일부 관여하는 것으로 생각되었다.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.133-140
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• 2012

A novel cry2Ab gene was cloned and sequenced from the indigenous isolate of Bacillus thuringiensis subsp. kurstaki. This gene was designated as cry2Ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kDa and pI value of 8.98. The amino acid sequence of the Cry2Ab25 protein was compared with previously known Cry2Ab toxins, and the phylogenetic relationships among them were determined. The deduced amino acid sequence of the Cry2Ab25 protein showed 99% homology to the known Cry2Ab proteins, except for Cry2Ab10 and Cry2Ab12 with 97% homology, and a variation in one amino acid residue in comparison with all known Cry2Ab proteins. The cry2Ab25 gene was expressed in Escherichia coli BL21(DE3) cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the Cry2Ab25 protein is about 70 kDa. The toxin expressed in BL21(DE3) exhibited high toxicity against Malacosoma neustria and Rhagoletis cerasi with 73% and 75% mortality after 5 days of treatment, respectively.

• Mycobiology
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• 제40권4호
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• pp.244-251
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• 2012

In vitro and greenhouse screening of seven rhizobacterial isolates, AB05, AB10, AB11, AB12, AB14, AB15 and AB17, was conducted to investigate the plant growth promoting activities and inhibition against anthracnose caused by Colletotrichum acutatum in pepper. According to identification based on 16S rDNA sequencing, the majority of the isolates are members of Bacillus and a single isolate belongs to the genus Paenibacillus. All seven bacterial isolates were capable of inhibiting C. acutatum to various degrees. The results primarily showed that antibiotic substances produced by the selected bacteria were effective and resulted in strong antifungal activity against the fungi. However, isolate AB15 was the most effective bacterial strain, with the potential to suppress more than 50% mycelial growth of C. acutatum in vitro. Moreover, antibiotics from Paenibacillus polymyxa (AB15) and volatile compounds from Bacillus subtilis (AB14) exerted efficient antagonistic activity against the pathogens in a dual culture assay. In vivo suppression activity of selected bacteria was also analyzed in a greenhouse with the reference to their prominent in vitro antagonism efficacy. Induced systemic resistance in pepper against C. acutatum was also observed under greenhouse conditions. Where, isolate AB15 was found to be the most effective bacterial strain at suppressing pepper anthracnose under greenhouse conditions. Moreover, four isolates, AB10, AB12, AB15, and AB17, were identified as the most effective growth promoting bacteria under greenhouse conditions, with AB17 inducing the greatest enhancement of pepper growth.

• IMMUNE NETWORK
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• 제3권2호
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• pp.118-125
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• 2003

Background: Disialoganglioside GD2 is a tumor-associated antigen that is overexpressed on tumor cells of neuroectodermal origin, such as melanoma and neuroblastoma. Anti-idiotypic antibodies that mimic GD2 may induce more effective immune responses than GD2 antigen itself, because they are protein antigens and are known to be able to break immune tolerance. In this study, to explore the potential of anti-idiotypic antibodies as tumor vaccines, the ability of anti-idiotypic antibodies (Ab2) to induce anti-anti-idiotypic antibodies (Ab3) that bind to the original antigen GD2 was investigated. Methods: Six monoclonal anti-idiotypic antibodies (1A8, 1G5, 2B6, 3A4, 3D6, 3H9) to monoclonal antibody M2058, which is a monoclonal antibody to GD2, were produced in mice. Three (1A8, 3A4, 3H9) of them were selected based on their ability to inhibit the binding of Ab1 to D142.34 (murine melanoma cell expressing GD2). These 3 different Ab2 were injected into rabbits, and rabbit Ab3 induced by each of them were characterized. Results: Ab3-containing sera from two rabbits immunized with 1A8, 3A4, or 3H9 bound significantly (P<0.05) to D142.34 but not to B78.96 (GD2-negative cell), and bound significantly (P<0.05) to isolated GD2 but not to GD1a. Ab3-containing sera from two rabbits immunized with 3A4 or 3H9 inhibited significantly (P<0.05) the binding of Ab1 M2058 to D142.34, and inhibited significantly (P<0.05) the binding of Ab1 M2058 to the Ab2. Conclusion: These results suggest that anti-idiotypic antibodies 3A4 and 3H9 have a potential to be used as vaccines against tumors expressing GD2 by inducing GD2-specific antibodies (Ab3).

• 대한금속재료학회지
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• 제50권3호
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• pp.256-262
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• 2012

This study investigated the hydrogen storage properties of Zr-Based $AB_{2-x}M_x$ metal hybride made by HCS (Hydriding Combustion Synthesis). The materials were prepared by HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm, HCS 80 wt% $AB_2$-20 wt% Mg and pure Zr-Based $AB_2$, These materials were activated at 298 K under 20 bar. Both HCS 80 wt% $AB_2$-20 wt% Mg and HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm were absorbed within 1 minute. In the case of the $AB_2$, it was perfectly absorbed within 6 minutes. Then, the materials were evaluated to obtain P-C-T (Pressure-Composition-Temperature) curves at 298K. As a result, the hydrogen storage capacity of HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ were determined to be 1.2, 1.6 and 1.74 wt%, respectively. The activation energy and rate controlling step were calculated by the Johnson-Mehl Avrami equation. The activation energies of HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ were 26.91, 20.45, and 60.41 kJ/mol, respectively. Also, the values of ${\eta}$ in the Johnson-Mehl Avrami equation for HCS 80 wt% $AB_2$-20 wt% Mg, HCS 80 wt% $AB_2$-15 wt% Mg-5 wt% Mm and pure Zr-Based $AB_2$ are 0.60, 0.51, and 0.44. So, the rate controlling steps which indicate hydrogen storage mechanism are an one dimensional diffusion process.

• 대한의생명과학회지
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• 제5권1호
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• pp.27-40
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• 1999

본 연구는 MarA와 함께 MarB가 AcrAB efflux pump를 목표로 하는지 여부, 그리고 항생제의 균체외 배출기능에 대하여 어떤 조절 작용이 있는지를 항생제 내성검사를 통하여 살펴보았다. 본 연구 결과는 MarB가 MarA와 함께 AcrAB/TolC efflux pump의 항생제 배출기 능을 억제적으로 조절한다는 것을 간접적으로 보여 주었으며, 한편 이미 알려진 대로 MarA는 acrRAB operon의 발현을 전사 수준에 서 positive regulation하므로, MarB는 AcrAB efflux pump의 기능을 억제적으로 조절한다는 것을 암시하고 있다. 그리고 MarA와 함께 MarB단백질의 작용 목표는 AcrAB efflux pump임을 간접적으로 보여주고 있다. 또한 MarB는 MarA와 함께 대장균의 다른 efflux system(들)의 항생제 배출기능에 대해서도 억제적으로 조절할 가능성이 높은 것으로 나타났다.

• BMB Reports
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• 제53권4호
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• pp.229-233
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• 2020

The anti-colorectal cancer monoclonal antibody CO17-1A (mAb CO), which recognizes the tumor-associated antigen EpCAM, was expressed in transgenic Arabidopsis plants. PCR and western blot analyses showed the insertion and expression of heavy chain (HC)/HC fused to the KDEL ER retention modif (HCK) and light chain (LC) of mAb CO and mAb CO with HCK (mAb COK) in Arabidopsis transformants. Both plant-derived mAb^P CO and mAb^P COK were purified from a biomass of approximately 1,000 seedlings grown in a greenhouse. In sandwich ELISA, both mAb^P CO showed a slightly higher binding affinity for the target, EpCAM, compared to mAb^M CO. In cell ELISA, both mAbs^P COs showed binding affinity to the human colorectal cancer cell line SW480. Furthermore, mAb^M CO, mAb^P CO, and mAb^P COK exhibited dose and timedependent regression effects on SW480 cells in vitro. In summation, both mAb^P CO and mAb^P COK, expressed in Arabidopsis, recognized the target antigen EpCAM and showed anti-proliferative activity against human colorectal cancer cells.

• IMMUNE NETWORK
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• 제7권3호
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• pp.141-148
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• 2007

Background: Anti-IgE mAb which binds circulating but not receptor-bound IgE has been shown to be effective in treatment for asthma and other allergic diseases. However, the mechanisms by which anti-IgE mAb influences the pathophysiological responses are remained to be illustrated. This study was undertaken to examine the therapeutic efficacy of non-anaphylactogenic anti-mouse IgE mAb using murine models of IgE-induced systemic fatal anaphylaxis. Methods: Active systemic anaphylaxis was induced by either penicillin V(Pen V) or OVA and passive systemic anaphylaxis was induced by either anaphylactogenic anti-mouse IgE or a mixture of anti-chicken gamma globulin (CGG) IgG1 mAb and CGG. The binding of the Fc portion of anti-IgE to CHO-stable cell line expressing mouse Fc ${\gamma}$ RIIb was examined using flow cytometry. Fc fragments of anti-IgE mAb were prepared using papain digestion. The expression of phosphatases in lungs were assessed by Western blotting and immunohistochemistry. Results: Anti-IgE mAb prevented IgE- and IgG-induced active and passive systemic fatal reactions. In both types of anaphylaxis, anti-IgE mAb suppressed antigen-specific IgE responses, but not those of IgG. Anti-IgE mAb neither prevented anaphylaxis nor suppressed the IgE response in Fc ${\gamma}$ RIIb-deficient mice. The Fc portion of anti-IgE mAb was bound to murine Fc ${\gamma}$ RIIb gene-transfected CHO cells and inhibited systemic anaphylaxis. Anti-IgE mAb blocked the anaphylaxis-induced downregulation of Fc ${\gamma}$ RIIb-associated phosphatases such as src homology 2 domain-containing inositol 5-phosphatase (SHIP) and phosphatase and tensin homologue deleted on chromosome ten (PTEN). Conclusion: Anti-IgE mAb prevented anaphylaxis by delivering nonspecific inhibitory signals through the inhibitory IgG receptor, Fc ${\gamma}$ RIIb, rather than targeting IgE.