• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.189-193
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• 2005

IgE-dependent histamine-releasing factor(HRF) was initially described as a secretagogue for secretion of histamine from IgE+ basophils from a subset of allergic donors. Previously, we identified that S98 residue of HRF was phosphorylated using anti-HRFpS98 antibody which specifically recognizes the phosphorylated serine residue of HRF and HRFS98A mutant construct. In vitro kinase assay, only wild type HRF was phosphorylated by PKC, and S98A HRF was not affected by PKC. In this study, we attempted to characterize the phosphatase which specifically dephosphorylates HRF by immunoprecipitation and pull-down assay. In RBL-2H3 cells, HRF interacted only with calcineurin (also called as PP2B, calcium/calmodulin-dependent phosphatase) but not with PP1 or PP2A. The results suggest that HRF is most likely dephosphory-lated by calcineurin.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.610-616
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• 1997

Hepatotoxic cyanobacteria, Microcystis species, were collected from the Nakdong River and we could isolate hepatotoxins, microcystin-LR and microcystin-RR, which are also strong inhibitors of protein phosphatase 1 and 2A. From the microcystins, several microcystin derivatives were synthesized and tested on the mouse toxicity in order to establish the structure-activity relationship. Esterification od carboxyl groups of Glu and MeAsp residue produced nontoxic compounds. However, when we reduced the Mdha residue with sodium borohydride into Ala residue, toxicity was still maintained. Also, the change of guanidyl moiety of Arg residue in microcystin-LR into dimethylpyrimidyl moiety did not change the toxicity of microcystins as well. Thus the carboxyl groups seem to play important roles in binding with protein phosphatase 1 and 2A, whereas Mdha residue and the guanidyl moiety of Arg residue do not.

• Journal of Microbiology
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• v.37 no.1
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• pp.21-26
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• 1999

Two novel calcium-binding proteins, named CAB-I and CAB-II, have been isolated from Streptomyces coelicolor. Purification of the calcium-binding proteins involved heat treatment, fractionation with ammonium sulfate, acid treatment, anion exchange and hydrophobic interaction column chromatography, FPLC gel filtration, and preparative isoelectric focusing. A chelex competitive assay and 45Ca autoradiography verified the calcium-binding ability of the proteins. The major band CAB-II has an apparent molecular weight of 26,000 determined by SDS-polyacrylamide gel electrophoresis and 340,000 determined by gel filtration. The isoelectric point of this molecule showed the acidic nature of the molecule. N-terminal amino acid sequence analysis shows homology to rat Ca2+/calmodulin-dependent protein kinase-II (CAB-II) and yeast phosphoprotein phosphatase (CAB-I).

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.146-152
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• 2003

Pyruvate dehydrogenase phosphatase (PDP) is a mitochondrial protein serine/threonine phosphatase that catalyzes the dephosphorylation and concomitant reactivation of the pyruvate dehydrogenase component of the pyruvate dehydrogenase complex (PDC). PDP consists of a catalytic subunit (PDPc, Mr 52,600) and regulatory subunit (PDPr, Mr 95,600). In the presence of $Ca^{2+}$, PDPc binds to the dihydrolipoamide acetyltransferase (E2) component of the pyruvate dehydrogenase complex in proximity to its substrate, the phosphorylated E1 component, thereby increasing the rate of dephosphorylation. PDPc possesses and intrinsic $Ca^{2+}$ binding site and a second $Ca^{2+}$ site is generated in the presence of E2. Using the unique interaction, highly pure PDPc was produced by the GSH-Sepharose-GST-L2 matrix with a specific activity of approx. 1000 U/mg and a yield of about 80%.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1023-1024
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• 2013

• KSBB Journal
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• v.7 no.1
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• pp.39-44
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• 1992

Dose-dependent responses indicated by the increase of leukocyte, peritoneal exudate cell and weights of immunorgans revealed the improvement of immunity. In the effect of macrophage on phagocytes, there were not substantial differences in the phagocytic and corrected phagocytic index. The administered group being compared with the controlled group, there were no significant changes in SGOT, S-GPT, alaline phosphatase, total protein, albumin, globulin, cholesterol, triglyceride, blood urea nitrogen and glucose. Key words: dose-dependent responses, peritoneal exudate cell, phagocytic idex, corrected phagocytic index.

• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.333-341
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• 1996

One of the biggest problems involved in transgenic animal production is lack of appropriate market genes. To overcome this problem, we tested whether the genes of SEAP (secreted alkaline phosphatase) and GFP (green fluorescence protein) on our retrovirus vectors can be applicable to the transgenic animal production. The main advantage of these marker genes over other generally mainpulation can be selected without sacrificing viability. The results obtained in this study are summarized as follows: 1. Removal of zona pellucida from the mouse zygotes did not affect embryo developments to blastocysts. 2. Co-culture of zona-free embryos with virus-producing cells for 6 hours also did not affect embryo developments to blastocysts. 3. Among 58 blastocysts developed from the zona-free zygotes co-cultured with the virus-producing cells, SEAP expression was observed from the 6 blastocysts. 4. Expression of the GFP gene was detected from the virus- producing cells but no embryo expressing the gene was counted among 50 blastocysts developed from the zona-free zygotes co-cultured with the virus-producing cells.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.90-96
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• 1994

Changes in haemolymph proteins, hydrolases such as esterase(EST), acid phosphatase(ACP) and alkaline phosphatase(ALP) , and inorganic ion(Na+, K+ and Cl- ) contents were induced by the injection of Bacillus thuringiengis into haemocoel of the last instar larva of Heliothis assulta. Protein concentration of haemolymph was increased until 24 hrs after injection, and decreased thereafter. Among the 8 basic protein bands identified through acid - polyacrylamide gel electrophoresis(PAGE), 2 bands(bands a and b) became stronger by the bacterial infection. Activities of EST and ALP increased until 12 hrs after injection and then fell down, whereas ACP activity was decreased continuously with time after injection. Contents of inorganic ions were all increased by the bacterial injection, showing slow rate of increase in the chloride ion, but rapid in the sodium and potassium ions.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.237-242
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• 1992

In order to clone the gene coding for alkaline phosphatase in the yeast Kluyveromyces fragilis, a genomic library was constructed using the yeast-E. coli shuttle vector pHN114 as a cloning vector. From the genomic library, a clone carrying the gene was isolated and the plasmid was designated as pSKH101. A restriction enzyme map was made using this plasmid. Subcloning experiments and complementation studies showed that alkaline phosphatase was active only in the original 3.1 kb insert. Southern hybridization analysis confirmed that the cloned DNA fragment was derived from K. fragilis genomic DNA. Using a minicell experiment, the product of the cloned gene was identified as a protein with a molecular weight of 63 KDa. A 0.6 kb HindIII fragment, which showed promoter activity, was isolated using the E. coli promoter-probe vector pKO-1.

• The Korea Journal of Herbology
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• v.37 no.1
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• pp.51-59
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• 2022

Objectives : The process through which mesenchymal cells condense and differentiate into chondrocytes to form new bone is known as endochondral bone formation. Chondrogenic differentiation and hypertrophy are essential steps in bone formation and are influenced by various factors. The stem bark and root bark of Eleutherococcus sessiliflorus (ES) have been widely used to treat growth retardation and arthritis in traditional Korean Medicine. In this study, we aimed to investigate the possible role of the stem bark of ES in the stimulation of chondrogenic differentiation in clonal murine chondrogenic ATDC5 cells. Methods : In ATDC5 cells treated with ES extract, cell viability and extracellular matrix production were determined using CCK-8 assay and Alcian blue staining, respectively, and alkaline phosphatase activity was measured. We also examined mRNA and protein expression levels of genes related to chondrogenic expression in ATDC5 cells using reverse transcription-polymerase chain reaction and western blot analyses. Results : ES extract increased the accumulation of Alcian blue-stained cartilage nodules and alkaline phosphatase activity in ATDC5 cells. It increased the mRNA expressions of chondrogenic markers including bone sialoprotein (BSP), cartilage collagens, Runt-related transcription factor-2 (RUNX-2), osteocalcin (OCN), β-catenin, and bone morphogenetic protein-2 (BMP-2), as well as the protein expressions of β-catenin, RUNX-2, BMP-2, and alkaline phosphatase (ALP). Conclusion : Taken together, these results suggest that ES extract exhibits a chondromodulating activity and therefore may be a possible agent for the treatment of bone growth disorders.