• Journal of Life Science
• /
• v.15 no.1 s.68
• /
• pp.71-79
• /
• 2005

The metabolism of lactate dehydrogenase (EC 1.1.1.27, LDH) and $C_4$ isozyme were studied in tissues of Coreoperca herzi and Pseudogobio esocinus acclimated to rapid increase of dissolved oxygen (DO). In C. herzi the LDH activity was changed $35-39\%$ in brain and liver tissues, and within $20\%$ in other tissues. The $B_4$ isozyme was increased and isozyme containing subunit C was decreased in muscle tissue. The $B_4$ isozyme was increased in heart and kidney. In P. esocinus, the LDH activity in liver tissues was largely increased to $150\%$ for 30 minute and $70\%$ in other tissues. The $A_4$ isozyme was increased in muscle and $B_4$ isozyme was increased in other tissues. Especially, the metabolism of liver tissue in P. esocinus was regulated by increasing liver-specific $C_4$ and decreasing $A_4$ isozyme. But the metabolism of eye tissue in C. herzi was regulated by decreasing LDH activity and eye-specific $C_4$ isozyme. The LDH activity and LDH isozyme in P. esocinus were largely increased than C. herzi acclimated to rapid increase of DO. And eye-specific $C_4$ and liver-specific $C_4$ isozymes played role as lactate oxidase. Therefore, the response of species acclimated to rapid increase of DO seems to be variable, perhaps due to prior exposure to environmental conditions.

• Biomedical Science Letters
• /
• v.23 no.3
• /
• pp.230-237
• /
• 2017

Changes in the activity of alkaline phosphatase (ALP) isoenzymes and isoforms in human serum have a major diagnostic value, therefore the regulation of ALP activities is a valuable target for therapeutic interventions. To assess the pharmacological activity of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, their tissue-specific inhibitory effect on human serum ALP activity was elucidated by chemical inhibition methods, heat-sensitive inactivation, and wheat-germ lectin precipitation test. Retinoids showed significant inhibition of the total ALP activity in human serum at a concentration of 5 mM. All-trans retinoic acid (5 mM) and 13-cis retinoic acid (5 mM) inhibited ALP activities by up to 12% and 15%, respectively, compared to that by guanidine hydrochloride (200 mM). L-phenylalanine (100 mM) and urea (30 mM) had no further inhibitory effect on ALP activities in human serum pretreated with retinoids (5 mM). Retinoids significantly inhibited ALP activities by up to 20% compared with that of tetramisole (30 mM). The ALP activities in retinoid-pretreated serum remained unchanged after the heat inactivation process. These results suggest that retinoids are inhibitors of the intestinal ALP isoenzyme. Remarkably, retinoids revealed potent inhibitory activities against ALP in wheat-germ lectin precipitant serum, indicating that they also function as inhibitors of the bone ALP isoform. The results show that retinoids inhibit the specific tissue-derived human serum ALP activities, moreover, the inhibitory effect of retinoids against bone ALP activity suggests their clinical utility as monitoring and prevention of metastasis of bone cancer.

• Journal of Plant Biology
• /
• v.38 no.1
• /
• pp.55-62
• /
• 1995

Embryogenic cell (EC) suspension cultures derived from mature seed-embryo of rice (Oryza sativa L cv. Kye Hwa) were used for the expression patterns of isozyme and enzyme activity. EC suspension cultures were composed of cells that were densely cytoplasmic, potentially embryogenic. However, nonembryogenic cell (NEC) cultures were composed of large, elongated and vacuolated cells. These cells were analyzed for the isozyme pattern and enzyme activity of EC and NEC. Isozyme patterns of peroxidase, esterase, acid phosphatase and malate dehydrogenase exhibited striking difference in the total number of bands, specificity and intensity of band. Also, these isozymes showed very high activity in the EC. Specific band, band activity and higher enzyme activity of isozyme in EC was absent or low in NEC, which may indicate an association of these specific isozymes with morphological characterization and totipotency of embryogenic cells. These results indicate that specific pattern and activity of enzyme in EC could probably be used as a biochemical marker of EC in rice.n rice.

• Journal of Ginseng Research
• /
• v.22 no.1
• /
• pp.51-59
• /
• 1998

In this study, rat hepatocytes known to have active glucose metabolism were obtained to investigate the hypoglycemic action of fat soluble fraction of red ginseng by using the liver perfusion technique and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only The activities of main regulating enzymes, such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenate, and glucose 6-phosphatase, related to metabolic pathways of glucose in these two kinds of hepatocytes were compared between these two groups and the effects of addition of fat soluble fraction ($10^1$~$10^4$%) from red ginseng to these two groups on these enzymes were also detected. The results were as follows. The specific activity of enzymes such as glucokinase, flucorse 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one. However, their decreased activity was recovered after the addition of fat-soluble fraction at all range of concentrations. The specific activity of these enzymes after the addition of ginseng components to the control group was also increased. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their increased activity was decreased obviously after the addition of fat soluble fraction at all range of concentrations. The same results were observed after the addition of fat-soluble fraction to the control group. These results suggest that the red ginseng saponin components might be effective on diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or indirectly. The effects of fat-soluble fraction ($10^2$%) and ginsenosides (mixture, $Rb_1$ and $Rg_1$, $10^4$%) on hypoglycemic action were compared. As a result, they showed considerable effect on hyperglycemia, but the best eff ect on the activities of glucokinase and glucose 6-phosphate dehydrogenase was appeared by ginsenoside $Rb_1$ and that of 6-phosphogluconate dehydrogenase and glucose 6-phosphatase was by ginsenoside mixture.

• BMB Reports
• /
• v.34 no.3
• /
• pp.212-218
• /
• 2001

Although the blockage of a cell cycle by specific inhibitors of $Ca^{2+}/$calmodulin-dependent protein kinase II (CaMK-II) is well known, the activity profile of CaMK-II during the cell cycle in the absence of any direct effectors of the enzyme is unclear. The activity of native CaMK-II in NIH 3T3 cells was examined by the use of cell cycle-specific arresting and synchronizing methods. The total catalytic activity of CaMK-II in arrested cells was decreased about 30% in the M phase, whereas the $Ca^{2+}$-independent autonomous activity increased about 1.5-fold in the M phase and decreased about 50% at the G1/S transition. The in vivo phosphorylation level of CaMK-II was lowest at G1/S and highest in M. The CaMK-II protein level was unchanged during the cell cycle. When the cells were synchronized, the autonomous activity was increased only in M. These results indicate that the physiologically relevant portion of CaMK-II is activated only in M, and that the net activation of CaMK-II is required in mitosis.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.11
• /
• pp.1501-1509
• /
• 2012

A novel bacterial strain, MG7, with high cellulase activity was isolated and identified by morphological characteristics and molecular phylogeny analysis as Paenibacillus barcinonensis. Maximum production of cellulase by MG7 was observed at pH 7.0 and $35^{\circ}C$. The enzyme was purified with a specific activity of 16.88 U/mg, the cellulase activity was observed in a zymogram, and its molecular mass (58.6 kDa) was confirmed by SDS-PAGE. The purified enzyme showed maximum activity at pH 6.0 and $65^{\circ}C$ and degraded cellulosic substrates such as carboxy methyl cellulose (CMC), Avicel, filter paper, and ${\beta}$-glucan. The enzyme showed stability with 0.5% concentration of various surfactants. The $K_m$ and $V_{max}$ of cellulase for CMC and Avicel were found to be 0.459mg/ml and 10.46mg/ml/h, and 1.01 mg/ml and 10.0 mg/ml/h, respectively. The high catalytic activity and its stability to temperature, pH, surfactants, and metal ions indicated that the cellulase enzyme by MG7 is a good candidate for biotechnological applications.

• Fisheries and Aquatic Sciences
• /
• v.13 no.4
• /
• pp.343-349
• /
• 2010

The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

• Microbiology and Biotechnology Letters
• /
• v.21 no.1
• /
• pp.30-35
• /
• 1993

Clp is a relatively abundant ATP-dependent protease found in E. coli. Its specific activity was proportional to the concentration of the limiting amount of Clp A and an excess amount of Clp P, and vice versa. Clp A has an intrinsic ATPase activity that is stimulated by casein, and contains a second site for binding A TP, in addition to the ATPase site. The modification of sulfhydryl groups in Clp A with reagents which have bulky groups such as N-phenylmaleimide led to nullifying both ATPase and protease activity. The same sites were modified by sulfhydryl reagents. It seems that the sulfhydryl groups of Clp A are not directly involved in catalysis. Since non-hydrolyzable analogs of ATP do not activate Clp, ATP hydrolysis may be essential for the proteolytic activity of Clp protease. Clp A and Clp P did not associate in the absence of nucleotide. The results suggest that the activity of the proteolytic component, Clp P, is regulated by the A TP-dependent cycling of Clp A between the activator form and the non-activator form.

• Korean Journal of Veterinary Research
• /
• v.44 no.3
• /
• pp.441-448
• /
• 2004

DNase activity in Haemonchus contortus reproductive tissue was characterized and compared to that in whole worm. DNase activity in reproductive tissue was detected throughout pHs 4-10 with high activity under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. The activity produced DNA fragments with mixtures of 3'-hydroxyls (OH) and 3'- phosphates (P) at each pH. Three distinct DNase activities were identified and had $M_rs$ of 34, 36 and 38.5 kDa in zymograms, which were distinguished according to pH requirement and sensitivity to EDTA. Among them, the 36 kDa reproductive tissue DNase had predominant activity at pH 5.0, but very weak at pH 7.0, and this activity was not inhibited by EDTA at pH 5.0. These characteristics of the 36 kDa reproductive tissue DNase resemble those of classic acidic DNases. In contrast, 36 kDa whole worm DNase activity had high activity at both pH 5.0 and 7.0. While the 36 kDa DNase activity at pH 5.0 was similar in both reproductive tissue and whole worm samples, the activity at pH 7.0 was predominantly detected in whole worm sample. This suggests that the 36 kDa whole worm DNase at pH 5.0 differs from that at pH 7.0. Thus, results indicate that the EDTA-insensitive 36 kDa DNase at pH 5.0 is specific for H. contortus reproductive tissue.

• Journal of Life Science
• /
• v.20 no.11
• /
• pp.1582-1588
• /
• 2010

A new alginate lyase gene of marine bacterium Streptomyces sp. M3 had been previously cloned in pColdI vector and transformed into E. coli BL21 (DE3). In this study, M3 lyase protein without signal peptide was overexpressed by induction with IPTG and purified with Ni-Sepharose affinity chromatography. The absorbance at 235 nm of the reaction mixture and TLC analysis showed that M3 alginate lyase was a polyG-specific lyase. When M3 lyase was assayed with substrate for 10 min, optimum pH and optimum temperature were pH 9 and $60^{\circ}C$. For the effect of 1mM metal ion on M3 lyase activity, $Ca^{++}$ and $Mn^{++}$ ions increased the alginate degrading activity by two-fold, whereas $Hg^{++}$ and $Zn^{++}$ ions inhibited the lyase activity completely. $Mg^{++}$, $Co^{++}$, $Na^+$, $K^+$, and $Ba^{++}$ did not show any strong effects on alginate lyase activity.