• 한국어병학회지
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• 제25권1호
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• pp.11-20
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• 2012

C-type lectins are crucial for pathogen recognition, innate immunity, and cell-cell interactions. In this study, a C-type lectin gene was cloned from the rock bream. The full-length RbCTL cDNA was 729 bp with a 429 bp ORF encoding a 164-residue protein. The deduced amino acid sequence of RbCTL had all of the conserved features crucial for its fundamental structure, including the four cysteine residues involved in sulfide bridge formation and potential $Ca^2+$/carbohydrate-binding sites. RbCTL contains a signal peptide one single carbohydrate recognition domain. It showed 29.4% similarity to the C-type lectin of rainbow trout. RbCTL mRNA was predominately expressed in gill and head-kidney tissue and expressed less in peripheral blood leukocytes, trunk-kidney, spleen, liver, intestine and muscle. Expression of RbCTL was differentially upregulated in rock bream stimulated with LPS, Con A/PMA and poly I:C.

• 약학회지
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• 제47권3호
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• pp.176-179
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• 2003

A library of unlimited number of novel lectins with diverse specificities has been previously generated by randomly mutating the carbohydrate-recognition domain of Maackia amurensis hemagglutinin (MAH). To establish the experimental environment capable of selecting high affinity mutant lectins in E. coli, phage display system was adapted. Carbohydrate binding capacity of two phagemid vectors, pComb3 and pComb8 displaying wild-type MAH lectin was assessed. Specific bindings of pComb3 and pComb8 phages expressing w.t. MAH to affinity-purified polyclonal anti-MAH antibody and to glycophorin was demonstrated. Both phages also showed strong hemagglutinating activity to intact but not sialidase-treated human erythrocytes, which is consistent to the specificity of native MAH. Taken together, two different phage display vectors successfully allowed the expression of active MAH as a fusion protein on the surface of bacteriophage, which will lead to preparation of unique plant lectins with high affinity toward a variety of carbohydrate chains.

• 대한수의학회지
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• 제37권3호
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• pp.547-554
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• 1997

Galectin-3 is known as an animal ${\beta}$-galactoside-binding lectin charicterized with S-type carbohydrate recognition domain. It plays a role in growth, adherence and movement of cells. It is, also, related to the cell transformation and metastasis of tumor cells. In this study, we have expressed and purified recombinant human galectin-3 (rHgalectin-3) using E coli system and asialofetuin affinity chromatography for the future development of monoclonal antibody to Hgalectin-3, which is suggested as the tumor marker for the gastric and thyroid gland cancers. Expressed protein was confirmed as the Hgalectin-3 by immunoblot with cross-reactive murine monoclonal antibody. Lectin activity and specificity of purified protein were, also, confirmed by the competitive inhibition with galectin-3 specific carbohydrate, lactose. Like physiological galectin-3, lectin activity of the molecule was not changed in nonreduced condition. Dimer formation, furthermore, was observed at high concentration of the protein even in the reduced condition, which is well known in physiological galectin-3. These results showed purified rHgalectin-3 has the same activity and molecular nature compared to the physiological galectin-3.

• The Plant Pathology Journal
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• 제21권4호
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• pp.301-309
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• 2005

Trichoderma species/isolates exhibited varied degree of agglutination on sclerotial (Sc) and hyphal (Hy) surface of Macrophomina phaseolina. The agglutination efficiencies on Sc and Hy ranged from $11\;to\;57\%$. Isolates of T. harzianum (Th) and T. viride (Tv) showed greater agglutination on Sc ($23-57\%$) and Hy ($16-47\%$). Different enzymes (trypsin, pepsin, proteinase k, a-chymotrypsin, lyticase and glucosidase) and inhibitors (tunicamycin, cycloheximide, brefeldin A, sodium azide, dithiothreitol and SDS) reduced the agglutination potential of conidia of Th-23/98 and Tv-25/98; however, the extent of response varied greatly in different treatments. Different fractions of Th-23/98 and Tv-25/98 exhibited haemagglutinating reaction with human blood group A, B, AB and O. Haemagglutinating activity was inhibited by different sugars and glycoproteins tested. Crude haemagglutinating protein from outer cell wall protein fraction of Th-23/98 and Tv-25/98 were eluted on Sephadex G-100 column. Initially Th-23/98 and Tv-25/98 exhibited two peaks showing no agglutination activity; however, lectin activity was detected in the third peak. Similar to crude lectin, the purified lectin also exhibited haemagglutinating activity with different erythrocyte source. SDS-PAGE analysis of partially purified lectin revealed single band with an estimated molecular mass of 55 and 52 kDa in Th-23/98 and Tv-25/98, respectively. Trypsin, chymotrypsin and b-1,3-glucanase totally inhibited lectin activity. Similarly, various pH also affected the haemagglutinating activity of Th-23/98 and Tv-25/98. From the present observations, it can be concluded that the recognition/attachment of mycoparasite (T. harzianum and T. viride) to the host surface (M. phaseolina) may be most likely due to lectin-carbohydrate interaction.

• ALGAE
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• 제24권1호
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• pp.39-45
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• 2009

The conjugation processes of a filamentous freshwater green alga Spirogyra varians were examined using FITC-lectins. Conjugation comprised five steps: 1) aligning with adjacent filaments, 2) formation of conjugation protru-sion (papilla), 3) fusion of the protrusions, 4) formation of conjugation tube,and 5) formation of zygotes. Three lectins, ConA, RCA and UEA, showed considerable labeling during the progression of conjuation. FITC-ConA labeled the surfaces of filaments throughout the whole conjugation processes. FITC-RCA labeling was observed at the conjugation protrusions only after the papilla formation. Strong labeling continued until formationg of zygotes at the contacting area where the conjugation tube developed, but no labeling was detected on the surface of vegetative filaments. The labeling decreased gradually over time and disappeared when zygotes were formed. FITC-UEA showed similar labeling pattern with FITC-RCA except that weak labeling remained after zygote formation. Inhibition experiments using RCA, UEA which are complementary to sugars L-fucose and D-galactose, showed considerable decrease of conjugation (<32% vs. 70% in control). These results suggested that the lectin-carbohydrate recognition system might be involved in the conjugation of spirogyra varians.

• 생명과학회지
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• 제19권2호
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• pp.284-288
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• 2009

선천성 면역은 숙주의 물리적 방어벽을 뚫고 침입하는 감염성 질병 원인균에 대항하는 첫 번째 방어로서 아주 중요한 역할을 한다. Mannose-binding lectin (MBL 또는 mannan-binding protein, MBP)은 혈청 내에 존재하는 면역성 단백질로서 감염 후 즉시 유발되는 acute phase response의 특정 단백질이다. MBL 단백질은 세균, 바이러스, 곰팡이, 기생충 등의 탄수화합물 구조에 결합하여 식균 작용을 돕거나 보체경로를 활성화 시킨다. MBL 단백질은 C-말단이 탄수화물을 인식하는 도메인이며, 연결 목 부위와 콜라겐 부위로 구성되어 있다. 혈청 내의 MBL 농도가 낮으면 높은 빈도로 면역결핍현상이 관찰된다고 알려져 있다. MBL 단백질의 기능과 유전에 대해 많은 연구가 되어져 왔으나 아직 MBL 단백질 복합체 등에 대한 연구는 많이 이루어져 있지 않다. 따라서 MBL 연구에 필수적인 MBL cDNA 제조와 재조합 단백질의 합성, 그리고 재조합 단백질을 항원으로 사용하여 polyclonal antibody를 생산한 연구 결과를 보고하는 바이다. 본 연구결과로 획득한 MBL cDNA, 재조합 단백질과 anti-MBL 항체는 앞으로의 MBL 연구에 절대적으로 필요한 도구가 될 것으로 생각된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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• pp.99-102
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• 2003

A cDNA of novel immulectin homologue (BmIML), a C-type lectin, was cloned from the silkworm, Bombyx mori. The immulectin cDNA is an open reading frame of 921 bp encoding 307 amino acid residues. The deduced amino acid sequence from the BmIML cDNA contains two C-type carbohydrate recognition domains (CRDs). The BmIML was most similar (61 % protein sequence identity) to the M. sexta immulectin-1, whereas BmIML showed relatively lower identity to the B. mori lipopolysaccharide-binding protein (25% protein sequence identity). These features of BmIML indicate that BmIML is a novel member of C-type lectin superfamily. Northern blot analysis revealed that the BmIML is specifically expressed in the fat body of B. moli larvae.

• 생명과학회지
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• 제23권3호
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• pp.347-354
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• 2013

선천성 면역은 감염성 매개체를 자기(self)로부터 변별할 수 있다. 선천성 면역은 감염 초기에 숙주인 자기를 보호하는 인식분자와 효과인자들로 구성되어 있다. Mannose 결합 렉틴(Mannose-binding lectin, MBL)은 $Ca^{2+}$ 의존형 렉틴에 속하며, 콜라겐 유사 domain을 함유하는 C-type 렉틴으로 선천성 면역의 중요한 분자이다. 혈액내 낮은 MBL 농도는 면역결핍 증후군을 나타내며 감염에 대한 심각한 위험성을 초래한다. 사람의 MBL 결핍증은 coding 영역의 돌연변이에 의해 나타나며, 이 돌연변이의 영향을 연구하기 위해 쥐의 상동성 유전자인 MBL-A를 이용하고 있다. 돌연변이 MBL의 기능적, 세포 생리적 연구를 위해 선행연구에서 rat wild type MBL-A 유전자를 클로닝하였으며, 본 연구에서 이 유전자에 콜라겐 유사 domain에서 발견된 세 가지 돌연변이, R40C, G42D, G45E를 site-directed mutagenesis 방법으로 모두 도입하였다. 세 가지 돌연변이가 존재하는 MBL 단백질은 정상 MBL과 마찬가지로 세포 내에서 정상적으로 발현되었으며, 여전히 렉틴 기능을 가지고 있었다. 이는 세 가지 돌연변이가 렉틴 기능을 나타내는 C-말단 쪽의 carbohydrate recognition domain에는 구조적으로, 또한 기능적으로도 영향을 미치지 않는다는 결과이다. 그러나 이 돌연변이는 MBL 단백질이 세포 밖으로 분비되는 것을 방해하였으며, 그 결과로 소포체 내에 잔류하여 소포체 망상구조(endoplasmic reticulumn network)에 커다란 손상을 주며 비정상적인 형체를 초래하였다. 이 같은 결과는 돌연변이 MBL에 의해 나타난 세포 내 병리현상의 새로운 발견으로 향후 MBL의 구조 형성과 분비 연구에 기여를 할 것으로 생각된다.

• BMB Reports
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• 제46권7호
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• pp.358-363
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• 2013

In this paper, we firstly reported a C-type lectin cDNA clone of 1029 bps from the larvae of A. Pernyi (Ap-CTL) using PCR and RACE techniques. The full-length cDNA contains an open reading frame encoding 308 amino acid residues which has two different carbohydrate-recognition domains (CRDs) arranged in tandem. To investigate the biological activities in the innate immunity, recombinant Ap-CTL was expressed in E. coli with a 6-histidine at the amino-terminus (Ap-rCTL). Besides acted as a broad-spectrum recognition protein binding to a wide range of PAMPs and microorganisms, Ap-rCTL also had the ability to recognize and trigger the agglutination of bacteria and fungi. In the proPO activation assay, Ap-rCTL specifically restored the PO activity of hemolymph blocked by anti-Ap-rCTL antibody in the presence of different PAMPs or microorganisms. In summary, Ap-rCTL plays an important role in insect innate immunity as an pattern recognition protein.

• BMB Reports
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• 제46권7호
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• pp.376-381
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• 2013

It is unknown how soluble pattern-recognition receptors in blood, such as mannose-binding lectin (MBL) and ficolins, modulate mast cell-mediated inflammatory responses. We investigate how mouse MBL-A or ficolin-A regulate mouse bone marrow-derived mast cells (mBMMCs)-derived inflammatory response against bacterial lipopolysaccharide (LPS) stimulation. LPS-mediated pro-inflammatory cytokine productions on mBMMCs obtained from Toll-like receptor4 (TLR4)-deficient mice, TLR2-defficient mice, and their wildtype, were specifically attenuated by the addition of either mouse MBL-A or ficolin-A in a dose-dependent manner. However, the inhibitory effects by mouse MBL-A or ficolin-A were restored by the addition of mannose or N-acetylglucosamine, respectively. These results suggest that mouse MBL-A and ficolin-A bind to LPS via its carbohydrate-recognition domain and fibrinogen-like domain, respectively, whereby cytokine production by LPS-mediated TLR4 in mBMMCs appears to be down-regulated, indicating that mouse MBL and ficolin may have an inhibitory function toward mouse TLR4-mediated excessive inflammation on the mast cells.