• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2447-2451
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• 2013

Objective: To study changes of tumor associated carbohydrate antigen (TACAs) expression and mRNA levels for tumor associated glycosyltransferases, and assess subcellular localizations of N-acetyl galactosyltransferases (GalNAc-Ts) in the K562 leukemia cell line after imatinib treatment. Methods: RT-PCR was performed to analyze the expression of glycosyltransferases which synthesize O-glycan in tumor-associated carbohydrate antigens (TCTAs). The expression of Tn antigen, T antigen and sialyl T antigen on K562 cell membranes was measured by flow cytometry after treatment with different concentrations of imatinib. Co-localization of GalNAc-Ts and ER (endoplasmic reticulum) was determined by confocal laser scanning microcopy. Results: Transcript expression levels of several glycosyltransferases related to TCTAs were decreased after imatinib ($0-0.3{\mu}M$) treatment. Expression of Tn antigen and T antigen was increased while that of sialyl T antigen was decreased. Co-localization of GalNAc-Ts and ER was reduced by $0.2{\mu}M$ of imatinib. Conclusion: Imatinib inhibited the expression of O-glycan related TACAs and several related glycosyltransferases, while decreasing the co-localization of GalNAc-Ts and ER and normalizing O-glycosylation in the K562 human leukemia cell.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.239-244
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• 2009

In order to alleviate the cyto-toxicity and improve the poor water solubility of 7-hydroxy-3-methoxycadalene, it was substituted with glucose, a strong hydrophilic and non cyto-toxiccompound, in the C-7 position. The yield of final product was ca. 55.4%. The $IC_{50}$ values of 7-O-${\beta}$-D-glucopyranosyl-3-methoxycadalene against normal lung cell (WI-38 cell line) and human lung cancer cell (A-549 cell line), which is a parameter for determination of cell viability, were measured to $298.2{\mu}m$ and $88.6{\mu}m$, respectively. This result indicates that the pharmaceutical efficiency of the cadalene-glucose derivative targeted to lung cancer cell could be improved more than three times compared to the non derivatized cadalene. In addition, glycosylation of 7-hydroxy-3-methoxycadalene turned its hydrophobic property to more soluble in water.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.931-937
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• 2018

Glycosyltransferases (GTs) from microbes are an emerging and rich source for efficient glycol-transformation of natural/unnatural compounds. Here, we probed the catalytic capability and substrate promiscuity of BmmGT1 from marine-derived Bacillus methylotrophicus B-9987. The regioselectivity of BmmGT1 on macrolactin A (1) was explored by optimization of the reaction conditions, in which a series of O-glycosylated macrolactins (1a-1e) were generated, including two new di/tri-O-glucosyl analogs (1b and 1e). Furthermore, BmmGT1 was able to catalyze the glycosylation of the thiol (S-) or amine (N-) sites of phenolic compounds (2 and 3), leading to the generation of N- (2a) or S-glycosides (3a and 3b). The present study demonstrates that BmmGT1 could serve as a potential enzyme tool for O-, N-, or S-glycosyl structural diversification of compounds for drug discovery.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.362-369
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• 2009

We have investigated the effect of glucosamine on the retinal cells after continuous infusion into cerebroventricle by using osmotic minipump to avoid peripheral effect. Continuous intracerebroventricular (i.c.v) infusion of glucosamine with the rate of 0.1 ${\mu}mol$/10 ${\mu}l$/hr for 7 days resulted in morphological changes of the optic nerve in electron microscopic level as well as morphological changes of the retina in light microscopic level. Retinal sections were immunostained for the detection of morphological changes of astrocytes. GFAP immunoreactivity appeared not only in the Muller cells but also many of the radial processes of Muller cells. The optic nerve showed deformed axon and slight lamellar separation of myelin sheath after continuous infusion of glucosamine in observing with electron microscope. Interestingly, vacuoles were observed in deformed axons and retinal layers were folded and detached. These results suggested that glucosamine plays a role in induction of morphological dysfunction in retina and optic nerves.

• Mycobiology
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• v.42 no.3
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• pp.241-248
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• 2014

NADPH oxidases (Noxes), transmembrane proteins found in most eukaryotic species, generate reactive oxygen species and are thereby involved in essential biological processes. However, the fact that genes encoding ferric reductases and ferric-chelate reductases share high sequence similarities and domains with Nox genes represents a challenge for bioinformatic approaches used to identify Nox-encoding genes. Further, most studies on fungal Nox genes have focused mainly on functionality, rather than sequence properties, and consequently clear differentiation among the various Nox isoforms has not been achieved. We conducted an extensive sequence analysis to identify putative Nox genes among 34 eukaryotes, including 28 fungal genomes and one Oomycota genome. Analyses were performed with respect to phylogeny, transmembrane helices, di-histidine distance and glycosylation. Our analyses indicate that the sequence properties of fungal Nox genes are different from those of human and plant Nox genes, thus providing novel insight that will enable more accurate identification and characterization of fungal Nox genes.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.614-618
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• 2014

Resveratrol, which is a polyphenolic antioxidant, is dose-dependent when used to provide health benefits, to enhance stress resistance, and to extend lifespans. However, even though resveratrol has therapeutic benefits, its clinical therapeutic effect is limited owing to its low oral bioavailability. An Escherichia coli system was developed that contains an artificial biosynthetic pathway that produces resveratrol glucoside derivatives, such as resveratrol-3-Oglucoside (piceid) and resveratrol-4'-O-glucoside (resveratroloside), from simple carbon sources. This artificial biosynthetic pathway contains a glycosyltransferase addition (YjiC from Bacillus) with resveratrol biosynthetic genes. The produced glucoside compounds were verified through the presence of a product peak(s) and also through LC/MS analyses. The strategy used in this research demonstrates the first harnessing of E. coli for de novo synthesis of resveratrol glucoside derivatives from a simple sugar medium.

• Mycobiology
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• v.42 no.4
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• pp.322-330
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• 2014

The aim of this study was to identify and characterize new Flammulina velutipes laccases from its whole-genome sequence. Of the 15 putative laccase genes detected in the F. velutipes genome, four new laccase genes (fvLac-1, fvLac-2, fvLac3, and fvLac-4) were found to contain four complete copper-binding regions (ten histidine residues and one cysteine residue) and four cysteine residues involved in forming disulfide bridges, fvLac-1, fvLac-2, fvLac3, and fvLac-4, encoding proteins consisting of 516, 518, 515, and 533 amino acid residues, respectively. Potential N-glycosylation sites (Asn-Xaa-Ser/Thr) were identified in the cDNA sequence of fvLac-1 (Asn-454), fvLac-2 (Asn-437 and Asn-455), fvLac-3 (Asn-111 and Asn-237), and fvLac4 (Asn-402 and Asn-457). In addition, the first 19~20 amino acid residues of these proteins were predicted to comprise signal peptides. Laccase activity assays and reverse transcription polymerase chain reaction analyses clearly reveal that $CuSO_4$ affects the induction and the transcription level of these laccase genes.

• BMB Reports
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• v.45 no.12
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• pp.742-747
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• 2012

Granulocyte colony-stimulating factor (G-CSF) is used for heart failure therapy and promotes myocardial regeneration by inducing mobilization of bone marrow stem cells to the injured heart after myocardial infarction; however, this treatment has one weakness in that its biological effect is transient. In our previous report, we generated 5 mutants harboring N-linked glycosylation to improve its antiapoptotic activities. Among them, one mutant (Phe140Asn) had higher cell viability than wild-type hG-CSF in rat cardiomyocytes, even after treatment with an apoptotic agent ($H_2O_2$). Cells treated with this mutant significantly upregulated the antiapoptotic proteins, and experienced reductions in caspase 3 activity and PARP cleavage. Moreover, the total number of apoptotic cells was dramatically lower in cultures treated with mutant hG-CSF. Taken together, these results suggest that the addition of an N-linked glycosylation was successful in improving the antiapoptotic activity of hG-CSF, and that this mutated product will be a feasible therapy for patients who have experienced heart failure.

• Journal of Life Science
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• v.31 no.7
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• pp.671-676
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• 2021

A cDNA encoding the protein lethal (2) essential for life [l(2)efl] was cloned from Gryllus bimaculatus and named GBl(2)efl. This protein is composed of 189 amino acids, including an N-glycosylation site and 15 phosphorylation sites. Its predicted molecular mass is 21.19 kDa, with a theoretical isoelectric point of 6.2. The secondary structure of GBl(2)efl was predicted from the identification of random coils (56.08%), alpha helices (22.22%), extended strands (17.99%), and beta turns (3.7%) through sequence analyses. A homology analysis revealed that GBl(2)efl exhibited a high similarity with other species at the amino acid level, ranging from 52% to 69%. While GBl(2)efl mRNA expression was higher in the dorsal longitudinal flight muscle following a three-day starvation and in the Malpighian tubules following a one-day starvation, no changes in expression were detected in other tissues. Furthermore, tunicamycin-induced endoplasmic reticulum (ER) stress resulted in an approximately 1.8-fold higher expression in the fat body compared with the wild type.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.719-732
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• 2003

A kojic acid derivative, kojic acid 7-O-$\beta$-D-tetraacetylglucopyranoside(KTG) was synthesized. Regio-and stereo-selective glycosylation at 7-postion in kojic acid with $\beta$-D-pentaacetylglucose was achieved with high yield(80％) by the use of Lewis acid and organic base in nonpolar solvent. KTG was hydrolyzed in methanol by the aid of sodium methoxide to give kojic acid 7-O-$\beta$-D-glucopyranoside(KGP). KGP is freely soluble in water and soluble in methanol and ethanol. Its structure was comfirmed by $^1$H-NMR and $^{13}$ C-NMR. Tyrosinase activity inhibition of KGP was measured with mushroom tyrosinase compared with ascorbic acid, kojic acid and arbutin. KGP showed higher tyrosinase inhibition activity($IC_{50}$/=33.3 $\mu\textrm{g}$/ml) than ascorbic acid(63.2 $\mu\textrm{g}$/ml) and arbutin(91.8 $\mu\textrm{g}$/ml) but lower inhibition activity than kojic acid(8.3 $\mu\textrm{g}$/ml). To test free-radical scavenging activity, we used 1, 1-diphenyl-2-picrylhydrazyl(DPPH) as a free-radical source. Free-radical scavenging activity of KGP was very low($SC_{50}$/>1000 $\mu\textrm{g}$/ml) compared with ascorbic acid($SC_{50}$/=2.68 $\mu\textrm{g}$/ml) and arbutin($SC_{50}$/=180$\mu\textrm{g}$/ml). Melanin formation inhibition of KGP was measured in B16 melanoma, compared with kojic acid, arbutin and Vitamin C. Inhibition activity of KGP for melanin formation was not found within test concentrations.