• Proceedings of the PSK Conference
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• 2000.10a
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• pp.147.1-147.1
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• 2000

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.133.2-133.2
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• 2001

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.685-692
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• 2001

Study the variation of low frequency electrical stimulation on human metabolism which serum to test the increasement of creatine- kinase, myoglobin, lactate .and pyruvate. The results were as followed: 1) Creatine kinase increasement showed significant difference between 200 Hz stimulation group and control group, and also between 300Hz stimulation group and control group, but no significant increasement difference showed in 50 Hz stimulation group compared to control group. 2) Lactate increasement showed significant difference in 200 Hz stimulation group and 300 Hz stimulation group compared to control group, but no significant difference showed in 50 Hz stimulation group. 3) Pyruvate increasement showed significant difference in 50 Hz stimulation group and 200 Hz stimulation group compared to control group, but no significant increasement difference showed between 50 Hz stimulation group and control group. (P < 0.05) 4) Myoglobin increasement showed significant difference in 50Hz stimulation group and 200 Hz stimulation group compared to control group, and also in 200 Hz stimulation group and 300 Hz stimulation group compared to 50Hz stimulation group. ( P < 0.05)

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.230-234
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• 2000

A new method to assay the capsaicinoid synthetase (CS) activity was developed by utilizing NADHcoupled enzyme systems involving pyruvate kinase and lactate dehydrogenase. CS activities in Capsicum placenta, depending upon the kinetics of the NADH oxidation, revealed almost the same profile as compared with those shown using an HPLC-based method. When the substrates, 8-methyl nonanoic acid and vanillylamine, for the CS enzyme were employed separately or simultaneously, it appeared that the two-step reaction, acyl-CoA formation and condensation with vanillyla~ne, of the CS enzyme was a coupled reaction. Thus, this assay method of the CS enzyme can be considered as an alternative to the HPLC-based method, since it has the advantages of rapidity and simplicity as well as reliability when compared with the existing method.

• Molecules and Cells
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• v.42 no.9
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• pp.628-636
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• 2019

Altered genetic features in cancer cells lead to a high rate of aerobic glycolysis and metabolic reprogramming that is essential for increased cancer cell viability and rapid proliferation. Pyruvate kinase muscle (PKM) is a rate-limiting enzyme in the final step of glycolysis. Herein, we report that PKM is a potential therapeutic target in triple-negative breast cancer (TNBC) cells. We found that PKM1 or PKM2 is highly expressed in TNBC tissues or cells. Knockdown of PKM significantly suppressed cell proliferation and migration, and strongly reduced S phase and induced G2 phase cell cycle arrest by reducing phosphorylation of the CDC2 protein in TNBC cells. Additionally, knockdown of PKM significantly suppressed $NF-{\kappa}B$ (nuclear factor kappa-light-chain-enhancer of activated B cells) activity by reducing the phosphorylation of p65 at serine 536, and also decreased the expression of $NF-{\kappa}B$ target genes. Taken together, PKM is a potential target that may have therapeutic implications for TNBC cells.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.495-500
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• 1986

Enzymatic micro-assay methods were studied those were capable of determining ammonia down to 10$^{-5}$M(0.01 $\mu$mole/ml) in the presence of other nitrogenous compounds such as protein and amino acid. Microquantities of ammonia (0.01-0.1 $\mu$mole) could be determined indirectly by measuring phosphorous, one of the products of the enzymatic reaction catalyzed by glutamine synthetase. In this reaction, L-glutamate, ATP and ammonium chloride were used as substrates, and phosphorous was formed in propotion to the concentration of ammonium chloride In the reaction mixture. Another procedure was examined in which glutamine synthetase reaction coupled with pyruvate kinase and lactate dehydrogenase reactions was used. One mililiter of the assay mixture contained; phosphoenol pyruvate, 3 mM, L-glutamate, 10 mM; ATP, 1mM: MgSO$_4$, 20 mM: KCl, 75mM: NADH, 0.2mM: Tris-HCl buffer(pH 7.0), 100mM; pyruvate kinase, 10 U: lactate dehydrogenase, 12 U and glutamine synthetase, 4 U. After preincubation for 20 min at 3$0^{\circ}C$, NH$_4$Cl was added and the rates of NADH oxidation were followed at 340nm. The effective range of this method was proved to be from 0.01 to 0.05 $\mu$mole/$m{\ell}$. Glutamine synthetase reaction coupled with glutamate synthase reaction could also be effectively used for determining microquantities of ammonia. The one mililiter assay mixture contained; ATP, 5mM: L-glutamate, 5mM; L-ketoglutarate, 5mM; MgCl$_2$, 15mM; NADPH, 0.15mM; Tris-HCl buffer(pH 7.0); 100mM; glutamine synthetase, 1U and glutamate synthase, 0.5U. After preincubation for 20min at 3$0^{\circ}C$ NH$_4$Cl was added and the rates of NADPH oxidation were followed at 340nm. The effective range of this procedure was appeared to be from 0.01 to 0.05$\mu$mole/$m{\ell}$.

• BMB Reports
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• v.32 no.2
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• pp.140-146
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• 1999

When murine fibrosarcoma L929 cells, a TNF-sensitive cell line, were treated with recombinant human tumor necrosis factor-$\alpha$ (rhTNF-$\alpha$), the activities of glycolytic regulatory enzymes and lactate dehydrogenase increased up to 100-150% compared to the control L929 cells after TNF treatment. By using various metabolic inhibitors and activators, it was found that cAMP-dependent protein kinase is responsible for the increase of activities of the glycolytic enzymes. The activities of glycolytic regulatory enzymes and lactate dehydrogenase of TNF-resistant A549 cells, a human lung carcinoma cell line, did not increase significantly compared to TNF-sensitive L929 cells upon TNF treatment. In contrast, the pyruvate carboxylase activities of A549 cells, but not L929 cells, increased up to 30~40% after TNF treatment. The data suggest that pyruvate carboxylase activity may contribute to the compensation of energy loss mediated by TNF treatment in TNF-resistant A549 cells.

• Molecules and Cells
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• v.28 no.3
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• pp.167-174
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• 2009

Genistein has been reported to potentiate glucose-stimulated insulin secretion (GSIS). Inhibitory activity on tyrosine kinase or activation of protein kinase A (PKA) was shown to play a role in the genistein-induced potentiation effect on GSIS. The aim of the present study was to elucidate the mechanism of genistein-induced potentiation of insulin secretion. Genistein augmented insulin secretion in INS-1 cells stimulated by various energygenerating nutrients such as glucose, pyruvate, or leucine/glutamine (Leu/Gln), but not the secretion stimulated by depolarizing agents such as KCl and tolbutamide, or $Ca^{2+}$ channel opener Bay K8644. Genistein at a concentration of $50{\mu}M$ showed a maximum potentiation effect on Leu/Gln-stimulated insulin secretion, but this was not sufficient to inhibit the activity of tyrosine kinase. Inhibitor studies as well as immunoblotting analysis demonstrated that activation of PKA was little involved in genistein-induced potentiation of Leu/Gln-stimulated insulin secretion. On the other hand, all the inhibitors of $Ca^{2+}$/calmodulin kinase II tested, significantly diminished genistein-induced potentiation. Genistein also elevated the levels of $[Ca^{2+}]_i$ and phospho-CaMK II. Furthermore, genistein augmented Leu/Gln-stimulated insulin secretion in CaMK II-overexpressing INS-1 cells. These data suggest that the activation of CaMK II played a role in genistein-induced potentiation of insulin secretion.

• Molecules and Cells
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• v.38 no.4
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• pp.373-379
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• 2015

Pyruvate kinase M2 isoform (PKM2), a rate-limiting enzyme in the final step of glycolysis, is known to be associated with the metabolic rewiring of cancer cells, and considered an important cancer therapeutic target. Herein, we report a novel PKM2 activator, PA-12, which was identified via the molecular docking-based virtual screening. We demonstrate that PA-12 stimulates the pyruvate kinase activity of recombinant PKM2 in vitro, with a half-maximal activity concentration of $4.92{\mu}M$, and effectively suppresses both anchorage-dependent and -independent growth of lung cancer cells in non-essential amino acid-depleted medium. In addition, PA-12 blocked the nuclear translocalization of PKM2 in lung cancer cells, resulting in the inhibition of hypoxia response element (HRE)-mediated reporter activity as well as hypoxia-inducible factor 1 (HIF-1) target gene expression, eventually leading to the suppression of cell viability under hypoxia. We also verified that the effects of PA-12 were dependent on PKM2 expression in cancer cells, demonstrating the specificity of PA-12 for PKM2 protein. Taken together, our data suggest that PA-12 is a novel and potent PKM2 activator that has therapeutic implications for lung cancer.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.834-841
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• 2019

Objective: This study was conducted to investigate the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the energy metabolism in thigh muscle of embryos and neonatal broilers. Methods: A total of 960 eggs were randomly assigned to three treatments: i) non-injected control group, ii) saline group injected with 0.6 mL of physiological saline (0.75%), and iii) CrPyr group injected with 0.6 mL of physiologi-cal saline (0.75%) containing 12 mg CrPyr/egg on 17.5 d of incubation. After hatching, 120 male chicks (close to the average body weight of the pooled group) in each group were randomly assigned to eight replications. The feeding experiment lasted 7 days. Results: The results showed that IOF of CrPyr increased glucose concentrations in the thigh muscle of broilers on 2 d after injection (p<0.05). Compared with the control and saline groups, the concentration of creatine in CrPyr group was increased on 2 d after injection and the day of hatch (p<0.05). Moreover, IOF of CrPyr increased the creatine kinase activity at hatch and increased the activities of hexokinase and pyruvate kinase on 2 d after injection and the day of hatch (p<0.05). Chicks in CrPyr group showed higher mRNA expressions of glucose transporter 3 (GLUT3) and GLUT8 on the day of hatch (p<0.05). Conclusion: These results demonstrated that IOF of CrPyr was beneficial to enhance muscle energy reserves of em-bryos and hatchlings.