• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.316.1-316.1
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• 2003

N-acetylneuraminic acid is one of the major derivatives of sialic acid. is widely distributed in mammalian cells as the ${\alpha}$2-3- or ${\alpha}$2-6-linked nonreducing terminal residue of oligosaccharide chains of glycoconjugates, and plays important structural and functional roles at the cell membrane surface. The analysis of sialylated glycoproteins is an important part of glycoprotein characterization, especially because sialylation or desialylation in oligosaccharides often causes dramatic changes in the function of glycoproteins. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.317.1-317.1
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• 2003

Carbohydrate-binding proteins have been isolated from various sources, including plants, animals, fungi, and bacteria, and they have been used extensively in the detection, localization, and isolation of glycoconjugates. Many carbohydrate-binding proteins are purified from mushrooms, however, only a few proteins with sialic acid-binding specificity have been reported. In the present study, a novel sialic acid-binding protein, designated PJA, has been purified from the mushroom Paecilomyces japonica. followed by extraction and affinity chromatography. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5601-5605
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• 2014

Background: Agrocybe aegerita Lectin (AAL) has been identified to have high affinity for sulfated and ${\alpha}2$-3-linked sialic acid glycoconjugates, especially the sulfated and sialyl TF (Thomsen-Friedenreich) disaccharide. This study was conducted to investigate the clinicopathological and prognostic value of AAL in identifying aberrant glycosylation in colorectal cancer (CRC). Materials and Methods: Glycoconjugate expression in 59 CRC tissues were detected using AAL-histochemistry. Clinicopathological associates of expression were analyzed with chisquare test or Fisher's exact test. Relationships between expression and the various clinicopathological parameters was estimated using Kaplan-Meier analysis and Cox regression models. Results: AAL specific glycoconjugate expression was significantly higher in tumor than corresponding normal tissues (66.1% and 46.1%, respectively, p=0.037), correlating with depth of invasion (p=0.015) and TNM stage (p=0.024). Patients with lower expression levels had a significantly higher survival rate than those with higher expression (p=0.046 by log rank test and p=0.047 by Breslow test for overall survival; p=0.054 by log rank test and P=0.038 by Breslow test for progress free survival). A marginally significant association was found between AAL specific glycoconjugate expression and overall survival by univariate Cox regression analysis (p=0.059). Conclusions: Lower AAL specific glycoconjugate expression is a significant favorable prognostic factor for overall and progress free survival in CRC. This is the first report about the employment of AAL for histochemical analysis of cancer tissues. The binding characteristics of AAL means it has potential to become a powerful tool for the glycan investigation and clinical application.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1293-1298
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• 2018

Phosphomannomutase (ManB) converts mannose-6-phosphate (M-6-P) to mannose-1-phosphate (M-1-P), which is a key metabolic precursor for the production of GDP-D-mannose used for production of glycoconjugates and post-translational modification of proteins. The aim of this study was to express the manB gene from Escherichia coli in Lactococcus lactis subsp. cremoris NZ9000 and to characterize the encoded enzyme. The manB gene from E. coli K12, of 1,371 bp and encoding 457 amino acids (52 kDa), was cloned and overexpressed in L. lactis NZ9000 using the nisin-controlled expression system. The enzyme was purified by Ni-NTA column chromatography and exhibited a specific activity of 5.34 units/mg, significantly higher than that of other previously reported ManB enzymes. The pH and temperature optima were 8.0 and $50^{\circ}C$, respectively. Interestingly, the ManB used in this study had two substrate specificity for both mannose-1-phosphate and glucose-1-phosphate, and the specific activity for glucose-1-phosphate was 3.76 units/mg showing 70% relative activity to that of mannose-1-phosphate. This is the first study on heterologous expression and characterization of ManB in lactic acid bacteria. The ManB expression system constructed in this study canbe used to synthesize rare sugars or glycoconjugates.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2002년도 제38회 학술심포지움
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• pp.13-19
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• 2002

To elucidate the regulatory mechanism for expression of sialyl-glycoconjugates and their biological functions, ninetheen sialyltransferase cDNAs including eleven by our group or co-works have been cloned and characterized so far. The cloned sialyltransferases are classified into four families according to the carbohydrate linkages they synthesize: ${\alpha}2,3-sialyltransferase$ (ST3Gal I-VI), ${\alpha}$ 2,6-sialyltransferase (ST6Gal I), GalNAc ${\alpha}$ 2,6-sialyltransferase (ST6GalNAc I-VI), and ${\alpha}2,8-sialyltransferase$ (ST8Sia I-VI). Each of the sialyltransferase genes is differentially expressed in a tissue-, cell type-, and stage-specific manner. These enzymes differ in their substrate specificity and various biochemical parameters. However, enzymatic analysis conducted in vitro with recombinant enzyme revealed that one linkage can be synthesized by multiple enzymes. We present here an overview of structure and function of sialyltransferases performed by our group and co-works. Genomic structures and transcriptional regulation of two kinds of human sialyltransferase gene are also presented.

• BMB Reports
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• 제45권8호
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• pp.442-451
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• 2012

Milk is an important fluid in glycobiology because it contains a number of short carbohydrate chains either free or as glycoconjugates. These compounds as a class are the most abundant component and benefit the infant by developing and maintaining the infant's gut flora. New and emerging methods for oligosaccharide analysis have been developed to study milk. These methods allow for the rapid profiling of oligosaccharide mixtures with quantitation. With these tools, the role of oligosaccharide in milk is being understood. They further point to how oligosaccharide analysis can be performed, which until now has been very difficult and have lagged significantly those of other biopolymers.

• Bulletin of the Korean Chemical Society
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• 제26권9호
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• pp.1347-1353
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• 2005

Sets of sialic acid-containing trisaccharides having different internal and terminal linkages have been synthesized to develop a sensitive method for analysis of the reducing terminal linkage positions. The trisaccharides, sialyl($\alpha$ 2-3)Gal($\beta$ 1-3)GalNAc and sialyl($\alpha$ 2-3)Gal($\beta$ 1-X)GlcNAc where X=3, 4 and 6, were synthesized and examined using electrospray ionization (ESI)-collision induced dissociation (CID) tandem mass spectrometry (MS/MS). The compounds chosen for this study are related to terminal groups likely to be found on polylactosamine-like glycoproteins and glycolipids which occur on the surface of mammalian cells. The purpose of this study is to develop tandem mass spectrometral methods to determine detailed carbohydrate structures on permethylated or partially methylated oligosaccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides to be used for further mass spectrometry and instrumental analysis.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.35-39
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• 2001

A simple method for studying the lectin-like interactions between Helicobacter pylori and cultured human epithelial cell lines was developed using an enzyme-linked, biotin-streptavidin bacterial-adhesion assay. The present study suggests that this method is suitable for evaluating the participation of lectin interactions in the adhesion of H. pylori to cultured HeLa S3 and Kato III cells, both fixed and glycosidase-treated cells, as well as assessing glycoconjugated binding inhibition studies. The time-course and dose-dependent kinetics of the biotin-labeled H. pylori adhesion th the formaldehyde-fixed Hela S3 and Kato III cell lines exhibited saturation. In addition, the binding of the biotin-labeled H. pylori to the formaldehyde-fixed cultured cells was partially blocked by pre-incubation with glycoconjugates and polyclonal antibodies against a heparan sulfate binding protein from H. pylori.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.146-147
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• 2001

Lectins or carbohydrate-binding proteins are proteins of non-immune origin, which is able to agglutinate cells, and precipitate polysaccharides and glycoconjugates (Goldstein et al., 1980). Lectins with diverse physiological roles are widely distributed to the various plant, microorganisms, invertebrates and vertebrates. The ubiquitous occurrence of lectins in nature and their ability to recognize complementary sugars provided a stimulus for the continuous research for their biochemical properties and physiological functions (Raz and Lotan, 1987). (omitted)

• Tuberculosis and Respiratory Diseases
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• 제41권3호
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• pp.248-261
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• 1994

연구배경 : Lectin은 탄수화물의 특정한 당잔기에 높은 친화성과 특이성을 가지므로 이러한 lectin-sugar 상호작용을 이용하여 사람 폐결핵결절에서 이를 구성하는 주된 성분인 건락성 괴사 상피양세포, 림프구 및 섬유층에 존재하는 탄수화물의 종류와 분포에 대해 알아보고자, 본 연구를 실시하였다. 방법 : 사람 폐결핵 절제 조직에서, 13종의 lectin을 사용하여 조직화학염색을 시행하였다. 결과: 1) 건락성 괴사부에서 BS $I-B_4$는 모든 구성성분에서, BS I는 변연부에 있는 일부의 세포성분을 제외하고 나머지 구성성분 모두에서 음성반응을 나타내었다. 그러나 나머지 lectin들은 건락성 괴사부에서 다양한 형태의 렉틴결합반응을 나타내었다. 2) 상피양세포들은 세포질에서의 반응 양상에 따라 크게 세 군으로 나눌 수 있었다. 첫째, DBA, UEA I 및 LCA는 대부분 중등도 이상의 강한 양성반응을 나타내었다. 둘째, WGA, s-WGA, PNA, SBA, VVL, ECL, PHA-L 및 PHA-E는 세포에 따라 다양한 형태의 반응양상을 나타내었다. 셋째, BS I 및 BS $I-B_4$는 음성반응을 나타내었다. 상피양세포의 세포막에 대한 결합반응을 살펴보았을 때, 첫째, ECL, PHA-L 및 PHA-E는 대부분 강한 양성반응을 보여주었다. 둘째, WGA, s-WGA 및 PNA는 세포에 따라 양성 및 음성반응이 혼재하는 양상을 나타내었다. 셋째, BS I, BS $I-B_4$, UEA I, DBA 및 VVL은 음성반응을 나타내었다. 3) 상피양세포사이물질들은 건락성 괴사부의 세포사이물질에 대한 lectin 결합 양상과 유사한 반응 양상을 나타내었다. 4) WGA, ECL, PHA-L, PHA-E 및 LCA들은 림프구에 강한 양성반응을 나타내었다. 5) SBA는 건락성 괴사부를 둘러싸는 섬유층의 외측에 위치하는 혈관 내피층에서 대체로 양성반응을 보였으나, 섬유층내의 혈관 내피층에서는 대체로 음성반응을 나타내었다. 6) PNA는 섬유층의 외측지역에서 양성반응을 나타내었지만 그와는 대조적으로 내측지역의 세포사이물질에서 음성반응을 나타내었다. 결론 : 이상의 결과와 같이, 렉틴결합특성을 이용한 조직화학적 연구는 사람 폐결핵 결절의 여러 성분들에 존재하는 복합당질의 종류, 특성 및 분포, 그리고 연결핵결절 형성과정 동안에 일어나는 복합당질 조성의 변화에 관한 유용한 정보를 제공해 주었으며, 이러한 결과들은 결핵결절의 병리학적 연구에 도움이 될 것으로 사료된다.