• Development and Reproduction
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• v.25 no.4
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• pp.199-211
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• 2021

Equine chorionic gonadotropin (eCG), produced by the endometrial cups of the placenta after the first trimester, is a specific glycoprotein that displays dual luteinizing hormone (LH)-like and follicle-stimulating hormone (FSH)-like effects in non-equid species. However, in equidaes, eCG exhibits only LH-like activity. To identify the specific biological functions of glycosylated sites in eCG, we constructed the following site mutants of N- and O-linked glycosylation: eCGβ/αΔ56, substitution of α-subunit⁵⁶ N-linked glycosylation site; eCGβ-D/α, deletion of the O-linked glycosylation sites at the β-subunit, and eCGβ-D/αΔ56, double mutant. We produced recombinant eCG (rec-eCG) proteins in Chinese hamster ovary suspension (CHO-S) cells. We examined the biological activity of rec-eCG proteins in CHO-K1 cells expressing the eLH/CG receptor and found that signal transduction activities of deglycosylated mutants remarkably decreased. The EC₅₀ levels of eCGβ/αΔ56, eCGβ-D/α, and eCGβ-D/αΔ56 mutants decreased by 2.1-, 5.6-, and 3.4-fold, respectively, compared to that of wild-type eCG. The Rmax values of the mutants were 56%-80% those of wild-type eCG (141.9 nmol/10⁴ cells). Our results indicate that the biological activity of eCG is greatly affected by the removal of N- and O-linked glycosylation sites in cells expressing eLH/CGR. These results provide important information on rec-eCG in the regulation of specific glycosylation sites and improve our understanding of the specific biological activity of rec-eCG glycosylation sites in equidaes.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.21-21
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• 2002

사람의 erythropoietin (hEPO) 는 산성 당단백질 호르몬이며 적혈구 생산의 주요조절인자로서 적혈구의 분화와 hemoglobin (Hb) 형성을 촉진하여 빈혈치료제로 이용된다. 사람 EPO 는 166개 아미노산으로 구성되어 있으며, 24, 38, 83 번 아미노산은 N-glycosylation에 의해, 126 번 아미노산은 O-glycosylation에 의해 변형되며, 특히 N-glycosylation은 hEPO 의 세포외 분비 및 활성에 관여한다고 보고된 바 있다. (중략)

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1639-1648
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• 2017

Curcumin is a natural polyphenolic compound, widely acclaimed for its antioxidant, anti-inflammatory, antibacterial, and anticancerous properties. However, its use has been limited due to its low-aqueous solubility and poor bioavailability, rapid clearance, and low cellular uptake. In order to assess the effect of glycosylation on the pharmacological properties of curcumin, one-pot multienzyme (OPME) chemoenzymatic glycosylation reactions with UDP-${\alpha}-{\text\tiny{D}}$-glucose or UDP-${\alpha}-{\text\tiny{D}}$-2-deoxyglucose as donor substrate were employed. The result indicated significant conversion of curcumin to its glycosylated derivatives: curcumin 4'-O-${\beta}$-glucoside, curcumin 4',4"-di-O-${\beta}$-glucoside, curcumin 4'-O-${\beta}$-2-deoxyglucoside, and curcumin 4',4"-di-O-${\beta}$-2-deoxyglucoside. The products were characterized by ultra-fast performance liquid chromatography, high-resolution quadruple-time-of-flight electrospray ionization-mass spectrometry, and NMR analyses. All the products showed improved water solubility and comparable antibacterial activities. Additionally, the curcumin 4'-O-${\beta}$-glucoside and curcumin 4'-O-${\beta}$-2-deoxyglucoside showed enhanced anticancer activities compared with the parent aglycone and diglycoside derivatives. This result indicates that glycosylation can be an effective approach for enhancing the pharmaceutical properties of different natural products, such as curcumin.

• Mass Spectrometry Letters
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• v.9 no.3
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• pp.67-72
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• 2018

Alkaline phosphatase (AP) is a membrane-bound glycoprotein that is widely distributed in the plasma membrane of cells of various organs and also found in many organisms from bacteria to humans. The complete amino acid sequence and three-dimensional structure of human placental alkaline phosphatase have been reported. Based on the literature data, AP consists of two presumptive glycosylation sites, at Asn-144 and Asn-271. However, it only contains a single occupied N-linked glycosylation site and no occupied O-linked glycosylation sites. Hydrophilic interaction chromatography (HILIC) has been primarily employed for the characterization of the glycan structures derived from glycoproteins. N-glycan structures from human placental alkaline phosphatase (PLAP) were investigated using HILIC-Orbitrap MS, and subsequent data processing and glycan assignment software. 16 structures including 10 sialylated N-glycans were identified from PLAP.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.74-83
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• 1993

In an attempt toward the synthesis of the difficulty accessible ginseng saponins the four dammarane glycosides identical to the natural $ginsenosides-Rh_2,$ - F2, compound K and chikusetsusaponin - LT8 have been prepared from betulafolienetriol(=dammar-24-ene-$3{\alpha},12{\beta}\;20(S)-triol).\;3-O-{\beta}-D-Glucopyranoside$ of 20(S) - protopanaxadiol $(=ginsenoside-Rh_2)$ have been obtained by the regio - and stereoselective glycosylation of the $12-O-acetyldammar-24-ene-3{\beta},\;12{\beta},$ 20(S)-triol. The 12-ketoderivative of 20(S)-protopanaxadiol has been used as aglycon in synthesis of chikusetsusaponin - LT8. Attempted regio - and stereoselective glycosylation of the less reactive tertiary C - 20 - hydroxyl group in order to synthesize the $20-O-{\beta}-D-glucopyranoside$ of 20(S)-protopanaxadiol(=compound K) using 3, 12 - di - O - acetyldammar - 24 - ene - $3{\beta},12{\beta},20(S)$-trial as aglycon was unsuccessful. Glycosylation of 3, 12 - diketone of betulafolienetriol followed by $NaBH_4$ reduction yielded the $20-O-{\beta}-D-glucopyranoside\;of\;dammar-24-ene-3{\beta},12{\alpha},$ 20(S)-triol, the $12{\alpha}-epimer$ of 20(S) - protopanaxadiol. Moreover, a number of semisynthetic ocotillol - type glucosides, analogs of natural pseudoginsenosides, have been prepared.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1092-1096
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• 2020

YjiC, a glycosyltransferase from Bacillus licheniformis, is a well-known versatile enzyme for glycosylation of diverse substrates. Although a number of O-glycosylated products have been produced using YjiC, no report has been updated for nucleophilic N-, S-, and C- glycosylation. Here, we report the additional functional capacity of YjiC for nucleophilic N- and S- glycosylation using a broad substrate spectrum including UDP-α-D-glucose, UDP-N-acetyl glucosamine, UDP-N-acetylgalactosamine, UDP-α-D-glucuronic acid, TDP-α-L-rhamnose, TDP-α-D-viosamine, and GDP-α-L-fucose as donor and various amine and thiol groups containing natural products as acceptor substrates. The results revealed YjiC as a promiscuous enzyme for conjugating diverse sugars at amine and thiol functional groups of small molecules applicable for generating glycofunctionalized chemical diversity libraries. The glycosylated products were analyzed using HPLC and LC/MS and compared with previous reports.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.257-262
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• 2007

The efficient synthesis of a tetrasaccharide, the suitably protected form of the repeat unit, →2)-α-D-Manp-(1→2)-β-D-Manp-(1→3)-α-D-GlcpNAc-(1→6)-α-D-Manp-(1→, of the O-antigen polysaccharide of the lipopolysaccharide from E. coli O77 has been accomplished. Glycosylation reactions for the coupling of four monosaccharide building blocks of the tetrasaccharide were carried out employing the CB glycoside method, the mannosyl 4-pentenoate/PhSeOTf method, and the glycosyl trichloroacetimidate method with complete stereoselectivities in excellent yields.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2493-2494
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• 2007

• Applied Microscopy
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• v.23 no.2
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• pp.84-96
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• 1993

This study was to investigate the effects of maternal diabetes on the lung tissue of the fetal rat using lectin histochemistry and electron microscope technique. Maternal diabetes was induced by intraperitoneal injection of streptozotocin (75 mg/kg the body weight) into pregnant Sprague-Dawley rats on the 7th day of gestation. Fetuses of streptozotocin induced diabetic rats exhibited delayed lung maturation and reduced air space. In lectin histochemistry, the binding of Maclura pomifera (MPA) to fetal lungs from diabetic mothers was reduced, but no significant changes in the bindings of Concanavalin A (Con A), Wheat germ agglutinin (WGA), Ricinus communis I (RCA I) and Griffonia simplicifolia (GSI-$B_4$) were noted. Because the MPA has affinity to terminal N-acetyl-D-galactosamine residues constantly linked O-glycosidically to serine or threonine, the present findings may indicates that maternal diabetes interfere with the processes of O-linked glycosylation in fetal rat lung.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1692-1700
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• 2021

Glycosylation of resveratrol was carried out by using the amylosucrase of Deinococcus geothermalis, and the glycosylated products were tested for their solubility, chemical stability, and biological activities. We synthesized and identified these two major glycosylated products as resveratrol-4'-O-α-glucoside and resveratrol-3-O-α-glucoside by nuclear magnetic resonance analysis with a ratio of 5:1. The water solubilities of the two resveratrol-α-glucoside isomers (α-piceid isomers) were approximately 3.6 and 13.5 times higher than that of β-piceid and resveratrol, respectively, and they were also highly stable in buffered solutions. The antioxidant activity of the α-piceid isomers, examined by radical scavenging capability, showed it to be initially lower than that of resveratrol, but as time passed, the α-piceid isomers' activity reached a level similar to that of resveratrol. The α-piceid isomers also showed better inhibitory activity against tyrosinase and melanin synthesis in B16F10 melanoma cells than β-piceid. The cellular uptake of the α-piceid isomers, which was assessed by ultra-performance liquid chromatography (UPLC) analysis of the cell-free extracts of B16F10 melanoma cells, demonstrated that the glycosylated form of resveratrol was gradually converted to resveratrol inside the cells. These results indicate that the enzymatic glycosylation of resveratrol could be a useful method for enhancing the bioavailability of resveratrol.