• Journal of Ginseng Research
• /
• v.22 no.2
• /
• pp.133-139
• /
• 1998

We have studied an activation mechanism of $pp60^{c-src}$ protein tyroslne kinase (PTK) by ginsenoside-$Rg_1$ (G-$Rg_1$ ) in NIH(pMcsrc/foc)B c-src overexpressor cells. It was previously reported that G--$Rg_1$ stimulated the activation of c-src kinase at 20 pM with a 18 hr-incubation, increasing the activity by 2-4-fold over that of untreated control, and this effect was blocked by treatments of in- hibitors of either protein synthesis (cycloheximide) or RNA synthesis (actinomycin D) (Hong, H.Y. et at. Arch. Pharm. Res. 16, 114 (1993)). However, an amount of c-src protein itself in wild-type cells was not changed by G-$Rg_1$. When the cells mutated at one or two tyrosine residue(s) (Y416/527) that are important sites to regulate the kinase activity were treated with G-$Rg_1$, increases both in the activity of c-src kinase and in the expression of the protein were not observed. In addition, removal of extracellular calcium ion by EGTA or inhibition of PKC by H-7 canceled the G-$Rg_1$-induced activation of the kinase. Although the activation was little affected by G-$Rg_1$ with a calcium ionophore A23187, it was synergistically stimulated by treatment of G-Rgl and PMA, a PKC activator. Taken together, these results suggest that the activation of c-src kinase by G-$Rg_1$ is caused by an increase in the specific activity of the kinase, but not in amount of it, and is involved with both collular calcium ion and PKC. Further the increase in the specific activity of c-src kinase may result from altered phosphorylation at tyro-416 and -527.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2003.02a
• /
• pp.28-28
• /
• 2003

• Archives of Pharmacal Research
• /
• v.29 no.11
• /
• pp.1006-1017
• /
• 2006

A series of 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-one, 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-thione and 2, 2'-dithiobis 3-(substituted-benylidene)-1, 3-dihydro-indole derivatives was investigated as inhibitor of $p60^{c-Src}$tyrosine kinase by performing receptor docking studies and inhibitory activity toward tyrosine phosphorylation. Some compounds were shown to be docked at the site, where the selective inhibitor PP1 [1-tert-Butyl-3-p-tolyl-1H-pyrazolo[3,4-d]pyrimidine-4-yl-amine] was embedded at the enzyme active site. Evaluation of all compounds for the interactions with the parameters of lowest binding energy levels, capability of hydrogen bond formations and superimposibility on enzyme active site by docking studies, it can be assumed that 3-(substituted-benzylidene)-1, 3-dihydro-indolin-2-one and thione derivatives have better interaction with enzyme active site then 2, 2'-dithiobis 3-(substituted-benzylidene)-1, 3-dihydro indole derivatives. The test results for the inhibitory activity against tyrosine kinase by Elisa method revealed that 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-thione derivatives have more activity then 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-one derivatives.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.33 no.1
• /
• pp.58-66
• /
• 2013

This study was conducted in order to develop slaughterhouse rumen content (SRC) as a potential feed additive. The moisture content of SRC can reach 80%, and therefore an appropriate dewatering process is required before it can be used. In this study, the effects of heating temperature, heating time, and filler content during the dewatering process on the activity of various enzymes in SRC were investigated. The Box-Behnken experimental design was employed, involving a total of 45 experimental runs, consisting of three variables (heating time, heating temperature, and filler content) with three levels per variable (12, 30 and 48 hr; 60, 75 and $90^{\circ}C$; 12, 22.5 and 33% for heating time, heating temperature, and filler content, respectively). For enzyme activities, xylanase, cellulase, and amylase were examined, and the results were subjected to an analysis of variance. Heating time, heating temperature and filler content had significant effects on the activity of each enzyme (p<0.05). Cellulase and amylase activities decreased (p<0.05) at elevated heating temperatures, whereas xylanase was reasonably stable around $90^{\circ}C$. The activities of all enzymes decreased (p<0.05) with increased heating time. Optimum filler contents for xylanase, cellulase, and amylase activities were 22.5, 12 and 33%, respectively. However, optimum conditions for all variables that simultaneously maximize the activity of all three enzymes could not be ascertained in this study. Nevertheless, the results from the current study can be useful as basic information for the development of SRC as a feed additive enriched with improved major enzymes for livestock feed digestion.