• BMB Reports
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• v.39 no.6
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• pp.774-781
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• 2006

Human nucleolar phosphoprotein p140 (hNopp140) is a nucleolar phosphoprotein that can bind to doxorubicin, an anti-cancer agent. We have examined the interaction between hNopp140 and doxorubicin as well as the folding property of hNopp140. Also, the effects of ATP and phosphorylation on the affinity of hNopp140 to doxorubicin are investigated by affinity dependent co-precipitation and surface plasmon resonance methods. Doxorubicin preferentially binds to un-phosphorylated form of hNopp140 with a $K_D$ value of $3.3\;{\times}\;10^{-7}$ M. Furthermore, doxorubicin reduces the protein kinase CK2-dependent phosphorylation of hNopp140, indicating that doxorubicin may perturb the cellular function of hNopp140 by reducing the protein kinase CK2-dependent phosphorylation of hNopp140. Low contents of the secondary structures of hNopp140 and the fast rate of proteolysis imply that hNopp140 has a high percentage of flexible regions or extended loop structures.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.936-941
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• 2000

To assess functional properties of chungkugjang (CK), a traditional Korean soyfood, fermented with black beans at $42^{\circ}C$ for 72 hrs, some biological activities of methanol extract of CK and the changes in phytoesterogen (daidzein, genistein) contents during fermentation were investigated. The methanol extract of CK (MEC) prepared with soybean had no or a little antibacterial activity. MEC prepared with black bean inhibited the growth of all bacteria tested, and MEC of small black bean was higher in antibacterial activity than that of large black bean. Hydrogen-donating activities of MEC of large and small black bean were 76.4 and 75.5%, respectively, which were higher than that of soybean being 67.3%. Nitrite-scavenging activity was found to be above 90% in all MECs tested as compared with control group. MEC showed strong antioxidant activities against both peroxidation of linoleic acid and $H_{2}O_{2}-FeSO_{4}-induced$ peroxidation of rat liver homogenate. The antioxidant activities were high in the order of small black bean, large black bean and soybean. Contents of genistein and daidzein were gradually increased during fermentation of CK. The isoflavones were higher in black bean CK than in soybean CK and higher in large black bean CK than in small black bean CK. In black beans genistein content was about twice as much of daidzein.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1170-1176
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• 2015

Ginsenosides, the major active component of ginseng, are traditionally used to treat various diseases, including cancer, inflammation, and obesity. Among these, compound K (CK), an intestinal bacterial metabolite of the ginsenosides Rb₁, Rb₂, and Rc from Bacteroides JY-6, is reported to inhibit cancer cell growth by inducing cell-cycle arrest or cell death, including apoptosis and necrosis. However, the precise effect of CK on breast cancer cells remains unclear. MCF-7 cells were treated with CK ($0-70{\mu}M$) for 24 or 48 h. Cell proliferation and death were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Changes in downstream signaling molecules involved in cell death, including glycogen synthase kinase $3\beta$ ($GSK3\beta$), $GSK3\beta$, $\beta$-catenin, and cyclin D1, were analyzed by western blot assay. To block $GSK3\beta$ signaling, MCF-7 cells were pretreated with $GSK3\beta$ inhibitors 1 h prior to CK treatment. Cell death and the expression of $\beta$-catenin and cyclin D1 were then examined. CK dose- and time-dependently inhibited MCF-7 cell proliferation. Interestingly, CK induced programmed necrosis, but not apoptosis, via the $GSK3\beta$ signaling pathway in MCF-7 cells. CK inhibited $GSK3\beta$ phosphorylation, thereby suppressing the expression of $\beta$-catenin and cyclin D1. Our results suggest that CK induces programmed necrosis in MCF-7 breast cancer cells via the $GSK3\beta$ signaling pathway.

• Journal of Ginseng Research
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• v.46 no.6
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• pp.780-789
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• 2022

Background: Incretin impairment, characterized by insufficient secretion of L-cell-derived glucagon-like peptide-1 (GLP-1), is a defining step of type 2 diabetes mellitus (T2DM). Ginsenoside compound K (CK) can stimulate GLP-1 secretion; however, the potential mechanism underlying this effect has not been established. Methods: CK (40 mg/kg) was administered orally to male db/db mice for 4 weeks. The body weight, oral glucose tolerance, GLP-1 secretion, gut microbiota sequencing, bile acid (BA) profiles, and BA synthesis markers of each subject were then analyzed. Moreover, TGR5 expression was evaluated by immunoblotting and immunofluorescence, and L-cell lineage markers involved in L-cell abundance were analyzed. Results: CK ameliorated obesity and impaired glucose tolerance in db/db mice by altering the gut microbiota, especially Ruminococcaceae family, and this changed microbe was positively correlated with secondary BA synthesis. Additionally, CK treatment resulted in the up-regulation of CYP7B1 and CYP27A1 and the down-regulation of CYP8B1, thereby shifting BA biosynthesis from the classical pathway to the alternative pathway. CK altered the BA pool by mainly increasing LCA and DCA. Furthermore, CK induced L-cell number expansion leading to enhanced GLP-1 release through TGR5 activation. These increases were supported by the upregulation of genes governing GLP-1 secretion and L-cell differentiation. Conclusions: The results indicate that CK improves glucose homeostasis by increasing L-cell numbers, which enhances GLP-1 release through a mechanism partially mediated by the gut microbiota-BA-TGR5 pathway. Therefore, that therapeutic attempts with CK might be useful for patients with T2DM.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5233-5236
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• 2012

CK2 is a serine threonine kinase that participates in a variety of cellular processes with more than 300 defined substrates. This critical enzyme is known to be upregulated in cancers, but the role of this upregulation in carcinogenesis is not yet fully understood but c-myc, one of the defined CK2 substrates, is a well-known proto-oncogene that is normally essential in developmental process but is also involved in tumor development. We evaluated the optimal enzyme and substrate concentrations for CK2 activity in both neoplastic and non-neoplastic human lung tissues using the c-$myc^{424-434}$ peptide (EQKLISEEDL) as a substrate. The activities measured for the neoplastic tissue were 600-750 U/mg protein while those for the control tissue was in the range of 650-800 U/mg. $K_m$ value for c-myc peptide was determined as $0.33{\mu}M$ in non-neoplastic tissue and $0.18{\mu}M$ in neoplastic tissue. In this study, we did not observe an increased activity in the neoplastic tissue when compared with the non-neoplastic lung tissue, but we recorded two times higher affinity for c-$myc^{424-434}$ in cancer tissue. Considering the metabolic position of c-$myc^{424-434}$, our results suggest that phosphorylation by CK2 may be important in dimerization and thus it might affect the regulation of c-myc in cancer tissues.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1762-1772
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• 2013

The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK) and the quality of mutton. One hundred and seventy-three (173) castrated sheep from Dormer (DM), South African Mutton Merino (SAMM), Dorper (DP) and Blackhead Persian (BP) sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months), Group 2 (9 to 12 months) and Group 3 (13 to 16 months). Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) were collected from 84 castrated sheep, of different breeds (28 per breed) 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH ($pH_{24}$), color ($L^*$, $a^*$ and $b^*$), thawing and cooking losses and Warner Braztler Shear Force (WBSF). The activity of plasma CK was significantly higher (p<0.001) in summer ($1,026.3{\pm}105.06$) and lower in winter ($723.3{\pm}77.75$). There were higher values for $L^*$ ($33.7{\pm}0.94$), $b^*$ ($11.5{\pm}0.48$) and WBSF ($29.5{\pm}1.46$) in summer season than in winter season; $L^*$ ($29.4{\pm}0.64$), $b^*$ ($10.2{\pm}0.33$) and WBSF ($21.2{\pm}0.99$). The activity of plasma CK was influenced by the type of breed with Dormer having the highest (p>0.001) levels ($1,358.6{\pm}191.08$) of CK. South African Mutton Merino had higher values for $pH_{24}$ ($5.9{\pm}0.06$), $L^*$ ($34.2{\pm}0.97$), $b^*$ ($12.2{\pm}0.50$) and WBSF ($26.8{\pm}1.51$) and Blackhead Persian had higher values ($35.5{\pm}2.17$) for cooking loss (CL%) than the other breeds. Computed Principal Component Analyses (PCA) on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between $pH_{24}$, $L^*$, $a^*$, $b^*$, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality.

• BMB Reports
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• v.42 no.3
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• pp.142-147
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• 2009

Small-molecule inhibitors of protein kinases have contributed immensely to our understanding of biological signaling path-ways and have been exploited therapeutically for the treatment of cancers and other disease states. The pyridinyl imidazole compounds SB 203580 and SB 202190 were identified as ATP competitive antagonists of the p38 stress-activated protein kinases and have been widely used to elucidate p38-dependent cellular processes. Here, we identify SB 203580 and SB 202190 as potent inhibitors of stress-induced CREB phosphorylation on Serine 111 (Ser-111) in intact cells. Unexpectedly, we found that the inhibitory activity of SB 203580 and SB 202190 on CREB phosphorylation was independent of p38, but instead correlated with inhibition of casein kinase 1 (CK1) in vitro. The inhibition of CK1-mediated CREB phosphorylation by concentrations of pyridinyl imidazoles commonly employed to suppress p38, suggests that in some cases conclusions of p38-dependence derived solely from the use of these inhibitors may be invalid.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.2005-2011
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• 2012

Nopp140 is a highly phosphorylated protein that resides in the nucleolus of mammalian cell and is involved in the biogenesis of the nucleolus. It interacts with a variety of proteins related to the synthesis and assembly of the ribosome. It also can bind to a ubiquitous protein kinase CK2 that mediates cell growth and prevents apoptosis. We found that Nopp140 is an intrinsically unfolded protein (IUP) lacking stable secondary structures over its entire sequence of 709 residues. We discovered that mitoxantrone, an anticancer agent, was able to enhance the interaction between Nopp140 and CK2 and maintain suppressed activity of CK2. Surface plasma resonance studies on different domains of Nopp140 show that the C-terminal region of Nopp140 is responsible for binding with mitoxantrone. Our results present an interesting example where a small chemical compound binds to an intrinsically unfolded protein (IUP) and enhances protein-protein interactions.

• Journal of Ginseng Research
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• v.46 no.4
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• pp.572-584
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• 2022

Background: Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of trinucleotide CAG repeat in the Huntingtin (Htt) gene. The major pathogenic pathways underlying HD involve the impairment of cellular energy homeostasis and DNA damage in the brain. The protein kinase ataxia-telangiectasia mutated (ATM) is an important regulator of the DNA damage response. ATM is involved in the phosphorylation of AMP-activated protein kinase (AMPK), suggesting that AMPK plays a critical role in response to DNA damage. Herein, we demonstrated that expression of polyQ-expanded mutant Htt (mHtt) enhanced the phosphorylation of ATM. Ginsenoside is the main and most effective component of Panax ginseng. However, the protective effect of a ginsenoside (compound K, CK) in HD remains unclear and warrants further investigation. Methods: This study used the R6/2 transgenic mouse model of HD and performed behavioral tests, survival rate, histological analyses, and immunoblot assays. Results: The systematic administration of CK into R6/2 mice suppressed the activation of ATM/AMPK and reduced neuronal toxicity and mHTT aggregation. Most importantly, CK increased neuronal density and lifespan and improved motor dysfunction in R6/2 mice. Conversely, CK enhanced the expression of Bcl2 protected striatal cells from the toxicity induced by the overactivation of mHtt and AMPK. Conclusions: Thus, the oral administration of CK reduced the disease progression and markedly enhanced lifespan in the transgenic mouse model (R6/2) of HD.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.419-423
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• 2014

The purpose of the present study was to investigate cardiac damage biomarkers after a triathlon race in elite and non-elite athlete groups. Fifteen healthy men participated in the study. Based on performance, they were divided into elite athlete group (EG: n＝7) and non-elite athlete group (NEG: n＝8). Participants' blood samples were obtained during four periods: before, immediately, 2 hours and 7 days after finishing the race. creatine kinase (CK), creatine kinase-myoglobin (CK-MB), myoglobin, and lactate dehydrogenase (LDH) were significantly increased in both groups immediately after, and 2 hours after finishing the race (p<.05). CK, CK-MB, and myoglobin were completely recovered after 7 days (p<.05). Hematocrit (Hct) was significantly decreased in both groups (p<.05) 7 days after the race. LDH was significantly decreased in the EG (p<.05) only 7 days after the race. Homoglobin (Hb) was significantly decreased in the NEG (p<.05) only 2 hours after the race. Although cardiac troponin T (cTnT) was significantly increased in the EG but not in the NEG 2hours after the race (p<.05), there was no group-by-time interaction. cTnT was completely recovered in both groups 7 days after the race. In conclusion, cardiac damage occurs during a triathlon race and, is greater in elite than in non-elite. However, all cardiac damage markers return to normal range within 1 week.