• Proceedings of the PSK Conference
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• 2003.04a
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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)

• Proceedings of the PSK Conference
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• 2003.04a
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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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• v.15 no.14
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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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• v.28 no.8
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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.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.12a
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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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• v.45 no.8
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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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• v.26 no.9
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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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• v.11 no.1
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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.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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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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• v.41 no.3
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• pp.248-261
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• 1994

Background: Lectins are proteins or glycoproteins of non-immune origin that recognize a specific sequence of sugar residues. The availability of a large number of lectins has provided the capacity to identify selectively glycoconjugates possessing distinctive chemical structure in diverse sites of highly specialized biological activity. The purpose of the present study was to investigate the lectin binding patterns of various components in human pulmonary tubercles. Method: Biopsy specimens of tuberculous lung were obtained from male adult patients who underwent a surgical resection for severe pulmonary tuberculosis. The specimens were processed and stained with 13 kinds of biotinylated lectins according to some modification of Hsu and Raine's methods. Results: 1) In the caseous necrotic lesions, BS $I-B_4$ showed negative reaction and BS I were also negative except some irregularly-shaped cells located in the marginal zone. All other lectins, however, showed a positive reaction with various binding patterns. 2) The epithelioid cells were broadly divided into three groups according to the reaction patterns in the cytoplasms and cell membranes. 3) WGA, ECL, PHA-L, PHA-E and LCA showed strong staining in the lymphocytes. 4) SBA showed a different binding patterns between the endothelial layers located in the region beyond the fibrous layers and those located within the fibrous layers. 5) PNA showed a positive reaction in the outer 1/3 to 1/2 of the fibrous layer, but showed no staining in the inner 1/2 to 2/3 of the fibrous layers. Conclusion: The present lectin histochemical study provided a useful information to assess the characterization and distribution of various glycoconjugates in each constituent of human pulmonary tubercles. The results demonstrate structural differences in the glycoconjugate composition of various components of the tubercles and reveal changes in glycosylation in the components during soft tubercle formation. This study provides a new data useful for the studies on the pathogenesis and pathology of human pulmonary tubercles.