• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.540-546
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• 2010

We investigated variations in alkaline phosphatase (APase) activity and alkaline phosphatase hydrolyzable phosphorus (APHP) in northern Gamak Bay from September to December 2009. Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) decreased gradually, and the DIN/DIP ratio was higher than the Redfield ratio (16) based on molecular concentrations during most of the observation period. The total APase (T-APase) activity increased with decreasing DIP concentration; i.e., the Relationship between T-APase and DIP showed a high negative correlation (r=-0.80, P<0.001), with APase activity being a good indicator of DIP limiting the Redfield ratio. The T-APase was positively correlated with the concentration of chlorophyll a (r=0.73, P<0.001). This suggests that a major portion of APase activity in northen Gamak Bay seawater is attributed to phytoplankton. The proportion of APHP among dissolved organic phosphorus (DOP) was low in September and high in November. Thus, APase-producing phytoplankton may be able to grow by utilizing APHP as a phosphorus source in autumn when DIP is limiting. Thus, APase activity and the use of DOP by phytoplankton may play an important role in the growth of phytoplankton under DIP limiting conditions such as those of northern Gamak Bay.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.425-432
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• 1993

Alkaline phosphatase from Culex pipiens pallens was examined to determine the optimal assay condition and to assay the activity during ovarian development. The activity of alkaline phosphatase in a male and a nongravid female continuously were declined after eclosion. But by the stimulus of a blood meal, the enzyme activity was increased dramatically. At 30 hr. after a blood meal, the maximal activity was reached and then declined. And after 48 hr. after a blood meal, the second activity increase was revealed. This second increase was maintained up to oviposition. The first activity increase was revealed in the midgut and the second increase was done in the ovary to assay the organ distribution of alkaline phosphatase. In electrophresis data, it was shown 5 isozyme bands, ALP-1 and ALP-2 in the ovary, ALP-3 in the thorax and the midgut, and ALP-4 and ALP-5 in the thorax, the fatbody and the midgut in crude extract at 30 hr. after a blood meal. One the same ovary pattern were shown at 72 hr. after a blood meal.

• Journal of Life Science
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• v.18 no.4
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• pp.585-589
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• 2008

Chronophin is a phosphatase responsible for the dephosphorylation of cofilin, which regulates the rearrangement of actin cytoskeleton. It is also known as a phosphatase for pyrodoxal 5'-phosphate (PLP), an active form of vitamin $B_6$, and maintains the level of PLP in the cytoplasm. Since this phosphatase belongs to a HAD subfamily containing a cap domain, it is expected to undergo a conformational change for the binding of a substrate. However, the crystal structure of chronophin has a disulfide bridge between the cap and core domains preventing a movement of the cap domain against the core domain. It is possible that the disulfide bond between C91 and C221 was formed by an oxidation during the crystallization. Here, we obtained chronophin crystals under a reduced condition and determined the crystal structure. This reduced chronophin does not contain a disulfide bridge and shows a closed conformation like the oxidized form. It implies that an active chronophin binds its substrate under the closed conformation without the disulfide bond and shows a high substrate specificity in the cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.490-495
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• 1994

Acid phosphatase (EC3.1.3.2) from carrots was partially purified by ammonium sulfate fractionation (30%-80%), Sephacryl S-200 gel filtration, cm-Sepharose CL-6B and DEAE -Sephacel ion exchange chromatography. The optimum ph and temperature of acid phosphatase from carrots were pH 5.5 and 55$^{\circ}C$, respectively. The enzyme was most stable at ph 6.0 and relatively unstable below pH 4.0 . The activation energy of the enayme was determined to be 10.6kcal/mole. The enzyme utilized p-nitrophenyl phosphate as a substrate among tested possible substrates, whereas it hydrolyzed 5' -IMP and 5'-GMP poorly. The Michaelis -Menten constant(Km) of the enzyme with p-nitrophenyl phosphate as a substrate was identified as 0.55mM. Amongtested metal ions and inhibitors, Al+++ Zn++, Cu++ , fluoride, metavanadate and molybdate ions inhibited the enzyme activity drastically.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.218-218
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• 1996

Brazilin은 포도당 수송을 증가시키는 물질로 autooxidation에 의하여 산화되면서 hydrogen peroxide를 생성할 것으로 추정되었으며, hydrogen peroxide는 phosphatase를 억제하여 포도당 수송을 증가시키는 것으로 보고되었다. 따라서 본 실험에서 brazilin의 산화에 의한 hydrogen peroxide의 생성여부를 확인하고 phosphatase 활성에 미치는 braziline의 작용을 살펴보았다. 먼저 UV absorption spectra를 이용하여 brazilin이 반응액중에서 구조적인 변화를 일으키는지 확인하였다. Hydrogen peroxide의 생성은 rhodamine 123를 이용한 형광측정법으로 측정하였으며, phosphatase의 활성은 pH에 따른 phosphatase의 활성을 p-NPP의 탈인산화의 UV 흡광도 변화로 측정하였다. PP2A의 활성은 phosphorylase a를 기질로 하여 측정하였다.

• 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.

• Korean Journal of Veterinary Research
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• v.11 no.2
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• pp.141-143
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• 1971

The serum alkaline phosphatase activity was determined with 64 Korean cattles in different sexe and age groups, using p-nitrophenylphosphate as the substrate. The results obtained were as follows: 1. The mean value of serum alkaline phosphatase activity in Korean cattle was $1.78{\pm}0.21$ Bessey-Lowry units/ml, and $1.71{\pm}0.21$ units/ml. in female and $1.86{\pm}0.21$ units/ml. in male, respectively. 2. The serum alkaline phosphatase activity decreased with age from 4 years group. 3. No statistical significance was recognized among the sexes, but difference among the age groups was found to be highly significant.

• IMMUNE NETWORK
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• v.5 no.3
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• pp.144-149
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• 2005

Background: Fc receptor-mediated phagocytosis is a complex process involving the activation of kinases and phosphatases. FcgammaRIIB has been known to transduces inhibitory signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. In this study, we examined the involvement of inositol-phosphatase in the Fc receptor-mediated phagocytosis. Methods: J774 cells were infected using vaccinia viral vector containing SH2 domain-containing inositol-phosphatase (SHIP) cDNA and stimulated with the sensitized sheep red blood cells. Results: Stimulation of J774 cells induced the tyrosine phosphorylation of SHIP which was maximal at 5 minutes. Phosphatidylinositol-3 (PI-3) kinase inhibitor (wortmannin) inhibits J774 cell phagocytosis of sensitized sheep red blood cells in a dose-dependent manner. Heterologious expression of SHIP in J774 cells inhibits phagocytosis of sensitized sheep red blood cells in a dose-dependency manner, but catalytically dead mutants of SHIP has no effect on phagocytosis. Conclusion: These results strongly suggest that the active signals mediated by PI-3 kinase are opposed by inhibitory signals through SHIP in the regulation of Fc receptor-mediated phagocytosis.

• Biomedical Science Letters
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• v.10 no.4
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• pp.429-434
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• 2004

The effects of intravenous administration of high concentration of taurocholic acid (TCA) on cathepsin B and D, and acid phosphatase activities in rat liver lysosome were studied. These liver lysosomal enzymes were determined from the experimental rats with choledocho-caval shunt (CCS). The activities of liver lysosomal cathepsin B and D, and acid phosphatase were found to be significantly increased in the CCS plus TCA injection group than in control group, such as group of CCS alone group. However, these hepatic enzyme activities did not change in the CCS plus tauroursodeoxycholic acid injection group. The above results suggest that TCA stimulates the biosynthesis of the lysosomal cathepsin B and D, and acid phosphatase in the liver.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.165-168
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• 1993

In order to know the enzyme activities of Filbricola seouzenis, an intestinal trematode of human and rodent in Korea. the enzyme histochemical method is applicated. Activities of acid phosphatase (E.C.3.1.3.2) and non-specific esterase (E.C.3.1.1) were present in microvilli and glandular cells of trlbocytic organ and the epithelium of the caecum.