• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.178-185
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• 2006

This study was to investigate the effect of 0.1% chitosan-ascorbate (CA) prepared with different molecular weight (223, 746, 1,110 and 2,025 kDa) of chitosan on the changes in antioxidant activity of mul-kimchi during storage at $10^{\circ}C$ for 20 days. Animal experiments were divided to 5 groups; normal control group (NC), high cholesterol diet group (HC), high cholesterol diet mul-kimchi diet group (HCKC), high cholesterol diet and CA2025 containing mul-kimchi administrated group (HCCA), and high cholesterol diet and 1/2 concentrated CA containing mul-kimchi administrated group (HC2CA). Mul-kimchi juice was administered 0.5 mL per 100 g body weight once a day and fed for 5 weeks. Electron donating activity of the 20 days-stored mul-kimchi with 0.1% CA showed higher activity (84.74~89.13%) than those of control and ascorbic acid mul-kimchi (35.04 and 75.04%). Superoxide dismutase activities of the kimchijuice with CA were higher in the higher molecular of chitosan. In the animal experiments, the average body weight of the HCCA and HC2CA group were lower 6.9% and 8.4% than that of HC control group, respectively. Hepatic glutathione content in HCCA and HC2CA group was increased 22.5% and 9.1% as compared to HC group. Hepatic glutathione S-transferase activities were significantly increased in the HCCA (219.9%) and HC2CA group (153.8%) compared to NC group. Hepatic superoxide dismutase activity was highest in the HCCA group, and the activities in CA groups were higher than those of NC and HC group.

• BMB Reports
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• v.44 no.10
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• pp.635-646
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• 2011

Due to its high external and low internal concentration the $Ca^{2+}$ ion is used ubiquitously as an intracellular signaling molecule, and a great many $Ca^{2+}$-sensing proteins have evolved to receive and propagate $Ca^{2+}$ signals. Among them are ion channel proteins, whose $Ca^{2+}$ sensitivity allows internal $Ca^{2+}$ to influence the electrical activity of cell membranes and to feedback-inhibit further $Ca^{2+}$ entry into the cytoplasm. In this review I will describe what is understood about the $Ca^{2+}$ sensing mechanisms of the three best studied classes of $Ca^{2+}$-sensitive ion channels: Large-conductance $Ca^{2+}$-activated $K^+$ channels, small-conductance $Ca^{2+}$-activated $K^+$ channels, and voltage-gated $Ca^{2+}$ channels. Great strides in mechanistic understanding have be made for each of these channel types in just the past few years.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.59-65
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• 1997

Bentazon 6-hydroxylase (B6H) and cinnamic acid 4-hydroxylase (CA4H) activities were determined in rice (Oryza sativa L.) microsomes to study methods of enhancing cytochrome P-450 mediated aryl hydroxylation of bentazon by hydoxylase inducing compounds. Pretreating rice seeds with 1,8-naphthalic anhydride at 0.5-2% and fenclorim at 5 and 10 ${\mu}M$ increased B6H and CA4H activities. Treatments of rice seedling with ethanol 2.5% enhanced B6H and CA4H activities, and with phenobarbital at 12 mM enhanced B6H activity, and CA4H activity was enhanced at 2 mM. B6H activity was synergistically enhanced by combined treatments of ethanol 2.5 or 5% and phenobarbital 8 or 12mM and also that of 1,8-naphthalic anhydride 0.5 or 1% and phenobarbital 8 or 12 mM, but CA4H activity was decreased by combined treatment. Five-day-old rice seedlings showed higher B6H and CA4H activities which decreased with seedling age.

• Journal of Microbiology
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• v.35 no.3
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• pp.200-205
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• 1997

Bothl $Ca^{2+}$ and Sr$^{2+}$-containing methanol dehydrogenases (MDH) were purified to homogeneity with yields of 48% and 42%, respectively, from Methylabacillus methanolovorus sp. strain SK5. Most of the biochemical and structural properties were similar to each other. However, some differences were found: (1) although the overall shape of the absorption spectrum of Sr$^{2+}$-MDH was very similar to that of $Ca^{2+}$-MDH, the absorption intensity originating from the cofactor in Sr$^{2+}$. MDH was higher than that in $Ca^{2+}$-MDH. Small blue shift of the maximum was also observed. These are probably due to a difference in redox state of the cofactors in $Ca^{2+}$ and Sr$^{2+}$-MDH; (2) Sr$^{2+}$-MDH was more heat-stable than $Ca^{2+}$-MDH above 56$^{\circ}C$; (3) the V$_{max}$ values for the methanol-dependent activities of Sr$^{2+}$- and $Ca^{2+}$-MDH in the presence of 3 mM KCN were 2.038 and 808 nmol/mg protein/min, respectively. In addition, the $K_{m}$ values of Sr$^{2+}$ and $Ca^{2+}$ MDH for methanol were 12 and 21 $\mu$M, respectively; (4) the endogenous activity of $Ca^{2+}$-MDH was more sensitive than that of Sr$^{2+}$-MDH in the presence of cyanide; (5) Diethyl pyrocarbonate treatment increased the enzyme activities of $Ca^{2+}$- and Sr$^{2+}$-MDH 4.2- and 1.4-folds, respectively. These results indicate that Sr$^{2+}$ stabilizes the structural conformation and enhances the activity of MDH more than $Ca^{2+}$.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.157-167
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• 1987

Benzyl alcohol is known to have dual effect on the red blood cell shape change. At low concentration up to 50 mM benzyl alcohol transformed the shape from discocyte to stomatocyte by preferent binding to the inner hemileaflet, however, at higher concentratransformed the shape from discocyte to stomatocyte by preferential binding to the inner monolayer, however, at higher concentration above 50 mM benzyl alcohol transformed to echinocyte by affecting both monolayers. These results suggest that the effect of benzyl alcohol on the red blood cell shape and $Ca^{++}$ transport across cardiac cell membranes to assess the effects of the drug on the structures and functions of the biological cell membranes. The results are as follows: 1) Benzyl alcohol up to 40 mM caused progressive stomatocytic shap change of the red blood cell but above 50 mM benzyl alcohol caused echinocytic shape change. 2) Benzyl alcohol up to 40 mM inhibited both osmotic hemolysis and osmotic volume change of the red blood cell in hypotonic and hypertonic NaCl solutions, respectively. 3) Benzyl alcohol inhibited both Bowditch Staircase and Wood-worth Staircase phenomena at rat left auricle. 4) Benzyl alcohol at concentration of 5 mM increased $Ca^{++}-ATPase$ activity of red blood cell ghosts slightly but above S mM benzyl alcohol inhibited the $Ca^{++}-ATPase$ activity. 5) Benzyl alcohol at concentrations of 5 mM and 10 mM increased $Ca^{++}-ATPase$ activity slightly at rat gastrocnemius muscle S.R. but above 10 mM benzyl alcohol inhibited the $Ca^{++}-ATPase$ activity. Above results indicate that benzyl alcohol inhibit water permeability and $Ca^{++}$ transport across cell membranes in part via effects on the fluidity and transition temperatures of the bulk lipid by preferential intercalation into cytoplasmic monolayer and in part via other effect on the conformational change of active sites of the $Ca^{++}-ATPase$ molecule extended in cytoplasmic face.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.453-457
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• 2006

This study investigated the extractability, solubility, Mg$^{2+}$-, Ca$^{2+}$- and EDTA-ATPase activity of actomyosin prepared from leg and breast muscle of dog meat. The actomyosin extractability of breast muscle(2,100.6 mg/l00 g) was higher than that of leg muscle(500.8 mg/l00 g). The Mg$^{2+}$-ATPase activity of actomyosin had a high ionic strength of 0.02$\sim$0.05 M KCI and did not differ between leg and breast muscle. The Ca$^{2+}$-ATPase activity of actomyosin had a high ionic strength of 0.02$\sim$0.10 M KCI and leg muscle had a higher level of Ca$^{2+}$-ATPase activity than breast muscle did. The EDTA-ATPase activity was lower in low ionic strength and showed higher in high ionic strength, and increased sharply with increasing ionic strength up to 0.3 M KCI. The solubility of actomyosin did not differ between leg and breast muscle, and the solubility started and ended at KCI concentrations of 0.35 M and 0.4 M, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.827-831
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• 1994

Investigation on the extractability, Mg2+-, Ca2+ , EDTA-ATPase activity and solubility of actomyosin prepared from leg and breast muscle of silky fowol were as follows. The extractability of actomyosin in leg and breast muscle was 779mg/100g and 1, 318mg/100g respectively, breast muscle was higher than leg muscle . Mg2+-ATPase activity of actomyosin was high inionic strength 0.02-0.10 and Mg2+ATPase activity of low ionic strength was higher than high ionic strength not related to the part. Ca2+ ATPase activity was high in ionic strength 0.05-0.13, the activity of leg muscle was higher that breast muscle. And EDTA-ATPase activity showed low in low ionic strength and showed high in high ionic strength, and increased greatly depend ionic strength up to 0.4. The solubility of actomyosin was not different in leg and breast muscle , the solution started in KCI concentration of 0.3M and ended in DCI concentration of 0.4M.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1839-1844
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• 2009

A 20-residue hybrid peptide CA(1-8)-MA(1-12) (CAMA) incorporating residues 1-8 of cecropin A (CA) and residues 1-12 of magainin 2 (MA) has high antimicrobial activity without toxicity. To investigate the effects of the total positive charges of CAMA on the antibacterial activity and toxicity, a hybrid peptide analogue (CAMA-syn) was designed with substitutions of $Ile^{10}\;and\;Ser^{16}$ with Lys. According to CD spectra, structure of CAMA-syn with increase of cationicity was very similar to that of CAMA in DPC micelle. CAMA-syn showed antimicrobial activity similar with CAMA while CAMA-syn has no hemolytic activity and much lower cytotoxicity against RAW 264.7 macrophage cells than CAMA. Also, CAMA and CAMA-syn significantly inhibited NO production by LPSstimulated RAW264.7 macrophage at 10.0∼20.0 $\mu$M. CAMA-syn displayed salt resistance on antimicrobial activity against Escherichia coli at the physiological concentrations of $CaCl_2\;and\;MgCl_2$. The combination studies of peptides and antibiotics showed that CAMA-syn has synergistic effects with synthetic compound and flavonoid against Enterococcus faecalis and VREF. CAMA-syn can be a good candidate for the development of new antibiotics with potent antibacterial and synergistic activity but without cytotoxicity.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.203-207
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• 1999

V. alginolyticus 138-2, a marine halophilic bacterium, produced an extracellular amylase with a molecular weight of ca. 56,000. The analysis of the digestion products of soluble starch by thin layer chromatography(TLC) revealed that the extracellular amylase of V. alginolyticus 138-2 is a saccharifying-type alpha-amylase. The alpha-amylase activity of the culture supernatant of soluble starch was optimal at pH 6.0 and 45$^{\circ}C$. Ca2+ slightly increased the alpha-amylase activity, whereas Hg2+, An2+, Cu2+, Ni2+, Fe2+, and Mn2+inhibited the enzymatic activity. Alkylating thiol group agent, iodoacetic acid did not affect the alpha-amylase activity, but reduced thiol reagents such as dithiothreitol, cysteine, and beta-mercaptoethanol stimulated theenzymatic activity. On the other hand, even if V. alginolyticus 138-2 is a marine halophilic bacterium, its alpha-amylase activity was significantly inhibited by NaCl.

• KSBB Journal
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• v.5 no.2
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• pp.119-124
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• 1990

Phospholipase D catalyzes the phosphatidohydrolysis and transphosphatidylation of phospholipid in the biological systems. In this study we were partially purified phospholipase D from Chinese cabbage and the characterization of the enzyme was carried out in a multistirring batch system bioreactor. The enzyme showed optimum activity at pH ,5.6, highest activity at 37$^{\circ}C$ and Ca2+ is important for the enzyme activity. Optimum concentrations of Ca2+ for phosphatidohydrolysis was 20 mM and for transphosphatidylation was 40 mM, respectively. Some organic solvents such as diethylether, isopropylether and butylacetate were activated the enzyme activity. On the other hand, EDTA, Ba2+, Mn2+ and Zn2+ showed inhibitory effect on the enzyme activity. The base acceptors in transphosphatidylation by the Chinese cabbage phospholipase D were tested. Various poly-and monohydroxy alcohols were found to be active.