• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.299-308
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• 2002

In horse, a single gene encodes both eCG and eLH $\beta$ subunits. The difference between eCG and eLH lies in the structure of their glycoresidues, which are both sialylated and sulfated in LH and sialylated in CG eCG consists of highly glycosyiated $\alpha$- and $\beta$-subunits and is an unique member of the gonadotropin family because it elicits response characteristics of both FSH and LH in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of gonadotropin structure-function relationships and the understanding of the molecular bases of the specific interactions of these hormones with their receptors. Thus, eCG is a dintinct molecule from the view points of its biological function and glycoresidue structures. The oligosaccharide at Asn 56 of the $\alpha$-subunit plays an indispensable role, whereas the carboxyl-terminal extension of the eCG $\beta$-subunit with its associated O-linked oligosaccharides is not improtant for, the in vitro LH-like activity of eCG. In contrast, both N- and O-linked oligosaccharides play important roles for FSH-like activity and increase FSH-like activity by removal of N- and O-linked oligosaccharides. Therefore, the dual LH- and FSH-like activities of eCG can be clearly separated by removal of either the N-linked oligosaccharide on the $\alpha$-subunit or CTP-associated O-linked oligosaccharides from its $\beta$-subunit. The glycoresidues seem to play crucial roles fer biological activities. The tethered-eCG was effciently secreted and showed similar LH-like activity to the dimeric eCG $\alpha$/ $\beta$ and native eCG. FSH-like activity of the tethered-eCG was also shown similarly in comparison with the native and wild type eCG $\alpha$/ $\beta$. Our data for the first time suggest that the tethered-eCG can be expressed efficiently and the produced product by the CHO-Kl cells is fully LH- and FSH-like activities in rat in vitro bioassay system. Our results also suggest that this molecular can imply particular models ot FSH-like activity not LH-like activity in the eCG. Taken together, these data indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion.

• 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.

• 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.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.501-505
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• 2021

The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri-induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.719-723
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• 2013

Nitrification in wastewater treatment emits a significant amount of nitrous oxide ($N_2O$), which is one of the major greenhouse gases. However, the actual mechanism or metabolic pathway is still largely unknown. Selective nitrification inhibitors were used to determine the nitrification steps responsible for $N_2O$ emission with activated sludge and enriched nitrifiers. Allylthiourea (86 ${\mu}M$) completely inhibited ammonia oxidation and $N_2O$ emission both in activated sludge and enriched nitrifiers. Sodium azide (24 ${\mu}M$) selectively inhibited nitrite oxidation and it led to more $N_2O$ emission than the control experiment both in activated sludge and enriched nitrifiers. The inhibition tests showed that $N_2O$ emission was mainly related to the activity of ammonia oxidizers in aerobic condition, and the inhibition of ammonia monooxygenase completely blocked $N_2O$ emission. On the other hand, $N_2O$ emission increased significantly as the nitrogen flux from nitrite to nitrate was blocked by the selective inhibition of nitrite oxidation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.691-695
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• 2016

Protein glycosylation is the most common posttranslational modification in mammalian cells. Aberrant protein glycosylation has been reported in various diseases, including cancer. We identified and quantified the glycan structures of O-linked glycoprotein from cholangiocarcinoma (CCA) cell lines from different histological types and compared their profiles by nanospray ionization-linear ion trap mass spectrometry (NSI-$MS^n$). Five human CCA cell lines, K100, M055, M139, M213 and M214 were characterized. The results showed that the O-linked glycans of the CCA cell lines comprised tri- to hexa-saccharides with terminal galactose and sialic acids: NeuAc1Gal1GalNAc1, Gal2GlcNAc1GalNAc1, NeuAc2Gal1GalNAc1 NeuAc1Gal2GlcNAc1GalNAc1 and NeuAc2Gal2GlcNAc1GalNAc1 All five CCA cell lines showed a similar glycan pattern, but with differences in their quantities. NeuAc1Gal1GalNAc1 proved to be the most abundant structure in poorly differentiated adenocarcinoma (K100; 57.1%), moderately differentiated adenocarcinoma (M055; 42.6%) and squamous cell carcinoma (M139; 43.0%), while moderately to poorly differentiated adenocarcinoma (M214; 40.1%) and adenosquamous cell carcinoma (M213; 34.7%) appeared dominated by $NeuA_{c2}Gal_1GalNA_{c1}$. These results demonstrate differential expression of the O-linked glycans in the different histological types of CCA. All five CCA cell lines have abundant terminal sialic acid (NeuAc) O-linked glycans, suggesting an important role for sialic acid in cancer cells. Our structural analyses of glycans may provide important information regarding physiology of disease-related glycoproteins in CCA.

• Journal of Animal Science and Technology
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• v.57 no.3
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• pp.12.1-12.5
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• 2015

Background: The Korean native pig (KNP) is generally thought to have come from northern China to the Korean peninsula approximately 2000 years ago. KNP pigs were at the brink of extinction in the 1980s, since then efforts have been made to restore the breed by bringing together the remaining stocks in South Korea. As a result, KNP was registered as a breed in 2006. To find additional breed-specific markers that are distinct among pig breeds, variations in O-linked N-acetylglucosamine transferase (OGT) were investigated. OGT is located on chromosome X and catalyzes the post-translational addition of a single O-linked-${\beta}$-N-acetylglucosamine to target proteins. Findings: Length polymorphism in the intron 20 of OGT was identified. The intron 20 of OGT from Duroc, Landrace, and Yorkshire breeds was 281-bp longer than that from either KNP or Chinese Meishan pigs. The difference between the Western pig breeds (BB genotype) and KNP or Meishan pigs (AA genotype) was due to an inserted 276-bp element and the 5-bp ACTTG. Conclusions: The polymorphism in OGT identified in this study may be used as an additional marker for determining the breed of origin among Meishan and the Western pig breeds. The length polymorphism suggests that the locus near OGT is not fixed in KNP. This marker would be relevant in determining the breed of origin in crossbred pigs between KNP pigs with known genotypes and the Western pig breeds with BB genotypes, thus confirming the contribution of the X chromosome from each breed.

• 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.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2517-2522
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• 2012

New polynuclear poly(hexaaza macrocyclic) copper(II) complexes $[1](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, $[2](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, and $[3](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$ have been prepared by the one-pot reaction of formaldehyde with ethylenediamine and 1,2-bis(2-aminoethoxy)ethane, 1,3-diaminopropane, or 1,6-diaminohexane in the presence of the metal ion. The polymer complexes contain fully saturated 14-membered hexaaza macrocyclic units (1,3,6,8,10,13-hexaazacyclotetradecane) that are linked by $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-N$, $N-(CH_2)_3-N$, or $N-(CH_2)_6-N$ chains. The mononuclear complex $[Cu(H_2L^5)](ClO_4)_4$ ($H_2L^5$ = a protonated form of $L^5$) bearing two $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-NH_2$ pendant arms has also been prepared by the metal-directed reaction of ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, and formaldehyde. The polymer complexes were characterized employing elemental analyses, FT-IR and electronic absorption spectra, molar conductance, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron micrograph (SEM). Electronic absorption spectra of the complexes show that each macrocyclic unit of them has square-planar coordination geometry with a 5-6-5-6 chelate ring sequence. The polymer complexes as well as $[Cu(H_2L^5)]^{4+}$ are quite stable even in concentrated $HClO_4$ solutions. Synthesis and characterization of the polynuclear and mononuclear copper(II) complexes are reported.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.465-469
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• 1998

The search for platinum (II)-based compounds with improved therapeutic properties was prompted to design and synthesize a new family of water-soluble, third generation cis-diaminedichloroplatinum (II) complexes linked to uracil and uridine. Six heretofore unreported uracil and uridine-platinum (II) complexes are; [N-(uracil-5-yl-methyl)ethane-1,2-di-amine]dichloroplatinum (II) (3a), [N-(uracil-6-yl-methyl)ethane-1,2-diaminel dichloroplatinum (II) (3b), t[N-($2^1$, $3^1$,$5^1$-tri-O-acetyl)uridine-5-yl-methyl] ethane-1,2-diamineldichloroplatinum (II) (6a), {[N-($2^1$,$3^1$, $5^1$-tri-O-acetyl) uridine-6-yl-methyl]ethane-1,2-diamine)dichloroplatinum (II) (6b),[N-(uridine- 5-yl-methyl)ethane-1,2-diamine]dichloroplatinum (II) (7a), [N-(uridine-6-yl- methyl)ethane-1,2-diamine]dichloroplatinum (II) (7b). These analogues were prepared from the key starting materials, 5-chloromethyluracil (1a) and 6-chloromethyluracil (1b) which were reacted with ethylenediamine to afford the respective 5-[(2-aminoethyl)aminol methyluracil (2a) and 6-[(2-aminoethyl)amino]methyluracil (2b). The cis-platin complexes 3a and 3b were obtained through the reaction of the respective 2a and 2b with potassium tetrachloroplatinate (II). The heterocyclic nucleic acid bases 1a and 1b were efficiently introduced on the .betha.-D-ribose ring via a Vorbruggen-type nucleoside coupling procedure with hexamethyldisilazane, trimethylchlorosilane and stannic chloride under anhydrous acetonitrile to yield the stereospecific .betha.-anomeric 5-chloromethyl- $2^1$,$3^1$,$5^1$-tri-O-acetyluridine (4a) and 6-chloromethyl-$2^1$,$3^1$,$5^1$-tri-O-acetyluridine (4b), respectively. The nucleosides 4a and 4b were coupled with ethylenediamine to provide the respective 5-[(amino-ethyl)aminolmethyl-$2^1$,$3^1$,$5^1$-tri-O-acetyluridine (5a) and 6-[(aminoethyl)amino] methyl-$2^1$,$3^1$,$5^1$-tri-O-acetyluridine (5b). The diamino-uridines 5a and 5b were reacted with potassium tetrachloroplatinate (II) to give the novel nucleoside complexes, 6a and 6b, respectively which were deacetylated into the free nucleosides, 7a and 7b by the treatment with CH$_{3}$ONa. The cytotoxic activities were evaluated against three cell lines (FM-3A, P-388 and J-82) and none of the synthesized compounds showed any significant activity.