• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6911-6917
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• 2014

Background: Hepatocellular carcinoma is a complex and heterogeneous tumor with poor prognosis due to frequent intrahepatic spread and extrahepatic metastasis. The molecular mechanisms underlying HCC pathogenesis still remain obscure. Objectives: We aimed to investigate the abundance and the DNA binding activity of nuclear factor kappa B/p65 subunit in peripheral blood mononuclear cells from patients with HCC and to assess its prognostic significance and association with hypoxia inducible factor one alpha (HIF-$1{\alpha}$) in blood. Subjects and methods: This study was carried out on 40 patients classified equally into liver cirrhosis (group I) and HCC (group II), in addition to 20 healthy volunteers (group III). All groups were subjected to measurement of NF-${\kappa}B$/P65 subunit expression levels by real time-PCR, and DNA binding activity was evaluated by transcription factor binding immunoassay. Serum HIF-$1{\alpha}$ levels were estimated by enzyme-linked immunosorbent assay (ELISA). Significant increase of both the expression level and DNA binding activity of NF-${\kappa}B$/P65 subunit together with serum HIF-1 alpha levels was noted in HCC patients compared to liver cirrhosis and control subjects, with significant positive correlation with parameters for bad prognosis of HCC. In conclusion, NF-${\kappa}B$ signaling is activated in HCC and associated with disease prognosis and with high circulating levels of HIF-1 alpha.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.671-679
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• 2010

The geometrical parameters and binding energies of the benzene ion-water complex [$C_6H_6^+-(H_2O)_n$(n=1-5)] have been investigated using ab initio (MP2) and density functional theory (DFT) with large basis sets. The harmonic vibrational frequencies and IR intensities are also determined to confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the binding energies. The predicted binding energy of 8.6 kcal/mol for $C_6H_6^+-(H_2O)$ at the MP2/aug-cc-pVTZ level of theory is in excellent agreement with recent experimental result of $8.5{\pm}1$ kcal/mol.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.757-763
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• 1999

The metal specificity of D-xylose isomerase from Streptomyces rubiginosus was examined by site-directed mutagenesis. The activation constants for metal ion ($Mg^{2+},{\;}Mn^{2+},{\;}or{\;}Co^{2+}$) of wild-type and mutant enzymes were determined by titrating the metal ion-free enzyme with $Mg^{2+},{\;}Mn^{2+},{\;}and{\;}Co^{2+}$, respectively. Substitutions of amino acids either on coordinated or around the M2 site (His-22O, Asn-185, Glu-186, and Glu-221) dramatically affected the activation constants as well as activity. A decrease of metal binding affinity was most significant in the presence of $Mg^{2+}$. When compared with the wild-type enzymes, the binding affinity of H220S and Nl85K for Mg^{2+} was decreased by 10-15-fold, while the affinity for $Mn^{2+}{\;}or{\;}Co^{2+}$ only decreased by 3-5-fold. All the mutations close to the M2 site changed their metal preference from $Mg^{2+}{\;}to{\;}Mn^{2+}{\;}or{\;}Co^{2+}$. These altered metal preferences may be caused by a relatively weak binding affinity of $Mg^{2+}$ to the enzyme. Thermal inactivation studies of mutants at the M2 site also support the importance of the M2 site geometry for metal specificity as well as the thermostability of the enzyme. Mutations of other important groups hardly affected the metal preference, although pronounced effects on the kinetic parameters were sometimes observed. This study proposes that the metal specificity of D-xylose isomerase can be altered by the perturbation of the M2 site geometry, and that the different metal preference of Group I and GroupII D-xylose isomerases may be caused by nonconserved amino acid residues around the M2 site.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2051-2056
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• 2009

The rate constants of alkaline fading of malachite green ($MG^+$) was measured in the presence of nonionic (TX-100), cationic (DTAB) and anionic (SDS) surfactants. This reaction was studied under pseudo-first-order conditions at 283∼303 K. The rate of fading reaction showed noticeable dependence on the electrical charge of the used surfactants. It was observed that the reaction rate constants were increased in the presence of TX-100 and DTAB and decreased in the presence of SDS. According to Hughs-Ingold rules for nucleophilic substitution reactions, the electric charge of MG/surfactant compound along with decrease in dielectric constant of $MG^+$ micro-environment in this compound varies the rate of fading reaction. Binding constants of surfactant molecules to $MG^+$ were calculated using cooperativity, pseudo-phase ion exchange and classical models and the related thermodynamic parameters were obtained by classical model. The results show that the binding of $MG^+$ to TX-100 is exothermic and binding of $MG^+$ to DTAB and SDS in some concentration ranges of the used surfactants is endothermic and in the other ones is exothermic.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.59-61
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• 1982

To evaluate the diagnostic value of the ratio of serum tyroxine$(T_4)$/thyroxine-binding globulin (TBG) for the thyroid status in pregnancy and newborn serum thyroxine, TBG, triiodothyronine, and free thyroxine levels were radioimmunoassayed in normal pregnant women at each of the trimesters, and the calculated serum $T_4/TBG$ ratios were compared with other parameters such as $T_3/TBG$ ratio and free $T_4/TBG$ ratio and free $T_4/TBG$ ratio. Serum $T_4$ levels were elevated with the propotionate increase in TBG levels during pregnancy, leading to the nearly constant value of serum $T_4/TBG$ ratios as in normal non-pregnant controls. In contrast, serum $T_3/TBG$ and free $T_4/TBG$ ratios varied considerably during pregnancy. In newborn, $T_4$ levels were nearly not changed with compared non-pregnant control value and TBG levels were elevated. The results indicate that serum $T_4/TBG$ ratio is a better parameter than others in evaluating the thyroid status during pregnancy and but newborn is a no better.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.351-359
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• 2012

Objectives: This study was conducted in order to investigate the specific correlation between physicochemical properties and bioactivity in ecdysteroids found in living organisms. Methods: The examined steroidal compounds were classified into three groups according to their relevance to ecdysone activity. Each compound molecule was completely drawn to automatically calculate its physicochemical parameters and docked against 20-hydroxyecdysone to calculate the total distance. Electronic charge distribution was also observed for each molecule. All procedures were conducted using a computational chemistry program. Results: Ecdysone agonists showed different ranges of parameter values, such as log P, hydrophilic-lipophilic balance (HLB), solubility parameter (SP), hydrophilic surface (HPS), hydrogen bond (HB) and Kappa 2, when compared with antagonists and steroids without ecdysone activity. They also showed a similar electronic charge distribution that is significantly different from the electron charge distribution of antagonists and steroids without ecdysone activity. The total distance values of agonists, estimated by docking them with 20-hydroxyecdysone, were relatively small but showed no correlation with binding affinity with receptor ligand. Conclusions: These results suggest that physicochemical properties such as steric and electronic effects, hydrophobicity and hydrogen bonding may operate in combination to determine the binding activity of ecdysteroids to the receptor protein.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.726-736
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• 2004

In this paper, kinetics of reaction between Bromophenol blue (BPB) and $OH^-$, called fading, has been studied through a spectrophotometric method in the presence of nonionic Triton X-100 (TX-100), anionic sodium dodecyl sulfate (SDS) and cationic dodecyl trimethylammonium bromide (DTAB) surfactants. The influence of changes in the surfactant concentration on the observed rate constant was investigated. The results are treated quantitatively by pseudophase ion-exchange (PPIE) model and a new simple model called "classical model". The binding constants of BPB molecules to the micelles and free molecules of surfactants, their stoichiometric ratios and thermodynamic parameters of binding have been evaluated. It was found that SDS has nearly no effect on the fading rate up to 10 mM, whereas TX-100 and DTAB interact with BPB which reduce the reaction rate. By the use of fading reaction of BPB, the binding constants of SDS molecules to TX-100 micelles and their Langmuir and Freundlich adsorption isotherms were obtained and when mixtures of DTAB and TX-100 were used, no interaction was observed between these two surfactants.

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.305-311
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• 1993

$Na^+,K^+$-ATPase activity, $Na^+$-dependent phosphorylation, and $[^3H]$ ouabain binding in sarcolemma prepared from 4 week old spontaneously hypertensive rat(SHR) ventricles were compared to the same parameters in sarcolemma from age matched nomotensive Wister-Kyoto (WKY) rat ventricles to examine whether the reduced myocardial $Na^+$-pump activity in SHR is an inherited enzymatic defect or a second phenomenon due to sustained hypertension. The total body weights, ventricular weights, and blood pressures were the same for SHR and WKY. No significant differences in sarcolemmal protein content and protein recovery were noted between the two groups. Sarcolemma isolated from SHR ventricles showed significantly less $Na^+,K^+$-ATPase activity ande number of phosphorylation sites when compared to sarcolemma from the WKY ventricles. Equilibrium binding of $[^3H]$ouabain and the tumover number of myocardial $Na^+,K^+$-ATPase, however, were the same for both groups. These reults indicate that the low affinity $(\alpha,\;or\;\alpha^1)\;\alpha$ isoform is the same in ventricles of SHR and WKY. The reduced amount of isoform of the $Na^+,K^+$-ATPase inprehypetensive SHR ventricles may play some role in the development of hypertension.

• Archives of Pharmacal Research
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• v.18 no.2
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• pp.113-117
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• 1995

We re-cloned mouse ${\delt}-Opioid$receptor from NG108-15 cells using RT-PCR, and confirmed it by restriction analysis and by sequencing the beginning and end part of the amplified DNA. When transiently expressed in COS-7 cells, cloned ${\delt}-Opioid$ receptor showed saturable and specific binding to $[^3H]$naloxone with very similar binding parameters to originally reported ones. To make antibodies specific for the ${\delt}-Opioid$ receptor, the carboxy tail of the receptor, which is unique to the ${\delt}-Opioid$ receptor compared with other opioid receptors, was expressed in bacteria as a ufsion proteinwith glutathione S-transferase. Purified fusion protein selective for ${\delt}-Opioid$ receptor when tested by western blotting using membrane proteins prepared from transfected COS-7 cells. Cloned ${\delt}-Opioid$ receptor andl antibodies specific for ${\delt}-Opioid$ receptor are going to be valuable tools for studying pharmacological actions of the ${\delt}-Opioid$ receptor and morphine dependence.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.204-211
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• 2006

This study investigated the effect of salt and glucono-${\delta}$-lactone (GdL) on the cold-set binding of restructured pork washed and pressurized at 200 MPa. Binding strength, PH, water holding capacity (WHC) and color were determined. NaCl improved pH, WHC and binding strength. GdL also increased binding strength while decreased WHC and pH significantly (p<0.05). However, low GdL level combined with NaCl showed high pH and WHC, compared to control. In color, NaCl decreased $L^*$-value with increasing $a^*$-value significantly (p<0.05). In contrast to NaCl, GdL increased $L^*$-value and decreased $a^*$-value. GdL tended to decrease $b^*$-value and significant differences were found when GdL was added above 1%. Pearson's correlation coefficients presented that NaCl had a significant effect on binding strength (0.6632) and lightness (-0.7330) while GdL had a significant correlation with all parameters barring binding strength. The results indicated that under washing and pressure treatments, GdL had a potential effect on cold-set binding with reducing NaCl concentration, especially when low GdL concentration combined with NaCl was added.