• BMB Reports
• /
• v.28 no.5
• /
• pp.387-391
• /
• 1995

In order to investigate whether phospholipase C (PLC) activity in oat celIs is regulated by Gprotein, we have characterized PLC in plasma membranes of oat tissues. To identify the purified plasma membrane, $K^+$-stimulated, $Mg^{2+}$-dependent ATPase activity was measured. The activity of ATPase was shown to be proportional to the concentration of membrane protein. To examine the PLC activity regulated by G-protein, we used the inside-out and outside-out plasma membrane mixture isolated from the oat cells. The plasma membrane mixture showed higher PLC activity than the one of the outside-out plasma membrane. This suggests that PLC activity is located at the cytoplasmic surface of plasma membrane. PLC activity in plasma membrane mixture was dependent on $Ca^{2+}$ with maximum activity at 100 ${\mu}m$ $Ca^{2+}$ and it was inhibited by 1 mM EGTA. Using Sep-pak $Accell^{TM}$ Plus QMA chromatography, we found that inositol 1,4,5-trisphosphate ($IP_3$) was produced in the presence of 10 ${\mu}m$ $Ca^{2+}$. The PLC activity in the membrane was enhanced by an activator of G-protein ($GTP{\gamma}S$) and not by an inhibitor ($GDP{\beta}S$). This indicates that a G-protein is involved in the activation of PLC in the plasma membrane of oat cells.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.2
• /
• pp.292-298
• /
• 1999

Myofibril and actomyosin were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their biochemical characteristics and SDS PAGE patterns of myofibril were compared. SDS PAGE analysis showed that electrophoretic patterns of myofibril were similar be tween white muscle and red muscle, while difference of 30kDa component of myofibril was detected between fresh water fish and sea water fish. When myofibril were treated with trypsin, difference in hydrolysis of heavy chain was observed between white muscle and red muscle. In activities of Ca ATPase, Mg ATPase, EDTA ATPase and ATPase activity pH curve, myofibrillar protein from fresh water fish showed higher specific activity than those from sea water fish.

• The Korean Journal of Pharmacology
• /
• v.2 no.1 s.2
• /
• pp.31-40
• /
• 1966

The microsomal fraction is isolated from rabbit heart and skeletal muscle. The fraction is found to contain the $Na^+$-and $K^+$-activated ATPase. The maximal ATPase activity is obtained in $Na^+$ and $K^+$ concentration of 100 mM. Calcium itself stimulates the $Na^+$-and $K^+$-activated portion of ATPase in the presence of $Mg^{++}$. However, calcium does not stimulate ATPase in the absence of $Mg^{++}$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.4
• /
• pp.348-352
• /
• 1992

Investigation on the characteristics of actomyosin was prepared from leg and breast muscle of duck treated by hard scalding and subscalding method and their extractability , ATPase activity , solubility and SDS polyacrylamide gel electrophoresis were compared. The extractability of actomyosin in leg and breast muscle of duck by hard scalding was 7.84 and 39.84mg/g, whereas 4.79 and 28.04mg/g by subscalding respectively. Ca-ATPase activity of breast muscle wash higher than that of leg muscle. In case of leg muscle, hard scalding was higher tan subscalding. Breast muscle showed that subscalding was higher than hard scalding in less than ionic strength 0.08, and was lower than hard scalding in over ionic strength 0.08.Mg-ATPase was great in ionic strength and subcalding was relatively higher than hard scalding. Without regard to be treated method and part, the start point and end point of solubility were like. Hard scalded muscle and breast muscle showed that proteins in thin filament produced many extraction.

• Proceedings of the Zoological Society Korea Conference
• /
• 1998.04a
• /
• pp.46.1-46
• /
• 1998

No Abstract, See Full Text

• Fisheries and Aquatic Sciences
• /
• v.2 no.1
• /
• pp.12-16
• /
• 1999

Denaturation of actomyosin from the obliquely striated mantle muscle of squids (Todarodes pacificus) was studied by measuring the changes in $Ca^{2+}$-ATPase activity, relative viscosity, and solubility during frozen storage at three different temperature zones of maximum ice crystal formation $(-3^{\circ}C,\;-\;-5^{\circ}C)$, the eutectic point $(-11^{\circ}C)$, and $-20^{\circ}C$. The logarithms of $Ca^{2+}$-ATPase activity, relative viscosity and solubility of the actomyosin solutions (0.6 M KCl) and suspensions (0.05 M KCl) tended to decrease during frozen storage. The denaturation of squid actomyosin at the zone of maximum ice crystal formation significantly differed by only two degree of temperature difference between $-3^{\circ}C$ and $-5^{\circ}C$, and it (0.05 M KCl) at $-3^{\circ}C$ was less than those of other temperature. The denaturation at $-11^{\circ}C$ was more rapid than at $-5^{\circ}C$. The logarithms of $Ca^{2+}$ -ATPase activity, relative viscosity, and solubility were changed slower in the suspensions (0.05 M KCl) than the solutions (0.6 M KCl) at all experimental temperatures.

• Korean Journal of Plant Resources
• /
• v.30 no.6
• /
• pp.647-653
• /
• 2017

Hepatic ischemia-reperfusion injury (HIRI) is linked with high mortality rate. Several agents have been developed so far to reduce the risk of HIRI. In this study, we investigated the effects of Acanthopanax senticosus extract (AS) on hepatic ischemia-reperfusion. To explore the protective effects of A. senticosus extract injection (ASI) on hepatic ischemia-reperfusion injury rats animal model were used. After the development of HIRI by using clamping method rats were then randomly divided into five groups. Different doses of AS were administered in HIRI rat model. The level of ALT, AST, and MDA content in serum were detected in sham and HIRI groups. The activity of SOD, MPO and $Ca^{2+}-ATPase$, content of MDA, and cAMP in hepatic tissue were also measured. Expression of Bcl-2 and Bax protein were detected by immunohistochemical staining method. Compared with sham group, ASI has the protective effect on the HIRI model in rats. Blood levels of ALT, AST, SOD, MPO, and MDA were significantly lower in ASI group compared with HIRI. Indeed SOD and $Ca^{2+}-ATPase$ activities, MDA content, and cAMP level were improved in ASI group. Furthermore, Bcl-2 and Bax protein were improved in ASI group compared with only HIRI group. These results suggest that AS may provide potential ameliorative therapy by inhibiting the damage signaling mechanism in hepatic ischemia/reperfusion injury model.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.4
• /
• pp.367-376
• /
• 1997

The effect of an organic peroxide, t-butylhydroperoxide (t-BHP), on glutamate uptake was studied in synaptosomes prepared from cerebral cortex. t-BHP inhibited the $Na^+-dependent$ glutamate uptake with no change in the $Na^+-independent$ uptake. This effect of t-BHP was not altered by addition of $Ca^{2+}$ channel blockers (verapamil, diltiazem and nifedipine) or $PLA_2$ inhibitors (dibucaine, butacaine and quinacrine). However, the effect was prevented by iron chelators (deferoxamine and phenanthroline) and phenolic antioxidants (N,N'-diphenyl-phenylenediamine, butylated hydroxyanisole, and butylated hydroxytoluene). At low concentrations (＜1.0 mM), t-BHP inhibited glutamate uptake without altering lipid peroxidation. Moreover, a large increase in lipid peroxidation by $ascorbate/Fe^{2+}$ was not accompanied by an inhibition of glutamate uptake. The impairment of glutamate uptake by t-BHP was not intimately related to the change in $Na^+-K+-ATPase$ activity. These results suggest that inhibition of glutamate uptake by t-BHP is not totally mediated by peroxidation of membrane lipid, but is associated with direct interactions of glutamate transport proteins with t-BHP metabolites. The $Ca^{2+}$ influx through $Ca^{2+}$ channel or $PLA_2$ activation may not be involved in the t-BHP inhibition of glutamate transport.

• Food Science of Animal Resources
• /
• v.18 no.2
• /
• pp.185-191
• /
• 1998

Human milk and bovine milk in normal stage were fractionated four parts : whey, skimmilk membrane, and casein pellet. The specific activity (nmole / mim / mg protein) and distribution ratio(%) of suborganella marker enzymes in each separated milk fraction were determined. Especially, neutral $Ca^{2+}$-ATPase, acid $Ca^{2+}$-ATPase, NADH-cytochrome C reductase, and acid phosphatase were higher in human milk. However, both $Ca^{2+}$-ATPases were not detected in all fractions of bovine milk. On the other hand, 5'-nucleotidase, phosphodiesterase I, alkaline phosphatase, and $\gamma$-glutamyl transpeptidase activities in bovine milk were higher than in human milk. Most of the marker enzymes were highly distributed in cream fraction of either human milk or bovine milk, and their specific activities were high to 24 fold from 3 fold when compared with that of whole milk. These results suggest that marker enzymes in mammary epitherial cell are transfered into cream fraction by the membrane rearrangement, and different biochemical reaction between human and bovine exists for milk secretion in mammary gland.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.468-474
• /
• 1997

This study was designed to investigate the changes in meat quality of beef shank, rib and loin during storage at 8$^{\circ}C$. The shear force value(SFV) of beef shank and loin decreased significantly after 6days storage, beef loin was no significant difference during storage. The SFV in early storage period was high in the order of beef rib, loin and shank, but the SFV of beef rib and loin was similar in course of storage period. The Myofibrillar fragmentation index(MFI) of beef shank increased significantly after 6 days storage, but beef rib and loin early storage was high in the order of beef rib, loin and shank. The actomyosin extractability after 3days storage increased in all parts of beef, but beef loin decreased after 6 days storage. In case of Mg2+-ATPase activity of actomyosin, beef shank increased to 3 days storage, and this reached the level of 0 day after 6days. The MG2+-ATPase activity of beef rib and loin was similar, but beef rib in early storage was higher than beef loin. The Ca2+-TPase activity of beef shank increased to 3 days and decreased after 6 days storage, beef rib was not different during storage and beef loin decreased slightly during storage.