• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.851-854
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• 2007

• Archives of Pharmacal Research
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• v.2 no.1
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• pp.65-70
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• 1979

Distribution and binding properties of sodium salicylate the human red blood cells were studied under various experimental conditions. The effect of tonicity and hemolysis on the steady state level of the drug within the human red blood cells were accounted for in this study. When the washed cells were suspended in normal saline solution, the drug was so rapidly permeated into red cells. Since the pH of the system forces nearly complete ionization of the drug, ionic diffusion through aqueous pores is thought to be the mode of salicylate transport. Human red cell binding capacity and association constant for salicylate were estimated. This work supports the view that the red cells act asan important reservior of salicylate.

• Molecules and Cells
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• v.24 no.1
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• pp.119-124
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• 2007

TLR4 together with CD14 and MD-2 forms a pattern recognition receptor that plays an initiating role in the innate immune response to Gram-negative bacteria. Here, we employed the surface plasmon resonance technique to investigate the kinetics of binding of LPS to recombinant CD14, MD-2 and TLR4 proteins produced in insect cells. The dissociation constants ($K_D$) of LPS for immobilized CD14 and MD-2 were $8.7{\mu}m$, and $2.3{\mu}m$, respectively. The association rate constant ($K_{on}$) of LPS for MD-2 was $5.61{\times}10^3M^{-1}S^{-1}$, and the dissociation rate constant ($K_{off}$) was $1.28{\times}10^2S^{-1}$, revealing slow association and fast dissociation with an affinity constant $K_D$ of $2.33{\times}10^6M$ at $25^{\circ}C$. These affinities are consistent with the current view that CD14 conveys LPS to the TLR4/MD-2 complex.

• BMB Reports
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• v.37 no.2
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• pp.159-166
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• 2004

Angiostatin is a potent anti-angiogenic protein. To examine the angiostatin-interacting proteins, we used the display-cloning method with a T7 phage library presenting human cDNAs. The specific T7 phage clone that bound to the immobilized angiostatin was isolated, and a novel gene encoding the displayed polypeptide on the isolated T7 phage was identified. The displayed angiostatin-binding sequence was expressed in E. coli as a soluble protein and purified to homogeneity. This novel angiostatin-binding region interacted specifically to angiostatin with a dissociation constant of $3.4{\times}10^{-7}\;M$. A sequence analysis showed that the identified sequence was a part of the large ORF of 1,998 amino acids, whose function has not yet been characterized. A Northern analysis indicated that the gene containing the angiostatin-binding sequence was expressed differentially in the developmental stages or cell types.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.89-102
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• 1982

The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

• Animal cells and systems
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• v.1 no.1
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• pp.77-80
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• 1997

DOantrolene is a primary specific therapeutic drug for prevention and treatment of malignant hyperthermia symptoms. The mechanisms underlying the therapeutic effects of the drug are not well understood. The present study aimed at the characterization of the effects of azumolene, a water soluble dantrolene analogue, on ryanodine binding to sarcoplasmic reticulum (SR) from normal and malign::lnt hyperthermia susceptible (MHS) swine muscles. Characteristics of $[^3H]ryanodine$ binding were clearly different between the two types of SR. Kinetic analysis of eH]ryanodine binding to SR in the presence of $2{\mu}M$ $Ca^{2+}$ showed that association constant $(K_{ryanodine}_7$ is significantly higher in MHS than normal muscle SR $(2.83 vs. 1.32{\times}10^7 M^{-1}$, whereas the maximal ryanodine binding capacity $(B_{max})$ is similar between the two types of SR. Addition of azumolene $(e.g. 400{\mu}M)$ did not significantly alter both $K_{ryanodine}$ and $B_{max}$ of $[^3H]$ryanodine binding in both types of SR, indicating that the azumolene effect was not on the ryanodine binding sites. Addition of caffeine activated $[^3H]$ ryanodine binding in both types of SR, and caffeine sensitivity was significantly higher in MHS muscle SR than normal muscle SR $(K_{caffeine}:3.24 vs. 0.82 {\times} 10^2 M^{-l}). Addition of azumolene $(e.g.400{\mu}M)$ decreased Kcaffeine without significant change in $B_{max}$ in both types of SR suggesting that azumolene competes with caffeine binding site(s). These results suggest that malignant hyperthermia symptoms are caused at least in part by greater sensitivity of the MHS muscle SR to the $Ca^{2+}$ release drug(s), and that azumolene can reverse the symptoms by reducing the drug affinity to $Ca^{2+}$ release channels.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.736-740
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• 2008

The interaction of myelin basic protein (MBP) from bovine central nervous system with divalent calcium ion was studied by isothermal titration calorimetry at 27 ${^{\circ}C}$ in aqueous solution. The extended solvation model was used to reproduce the enthalpies of $Co^{2+}$-MBP interaction over the whole $Co^{2+}$ concentrations. The solvation parameters recovered from the solvation model were attributed to the structural change of MBP due to the metal ion interaction. It was found that there is a set of three identical and noninteracting binding sites for $Co^{2+}$ ions. The association equilibrium constant is 0.015 ${\mu}M^{-1}$. The molar enthalpy of binding is $\Delta$H = −14.60 kJ $mol^{-1}$.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.495-503
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• 1994

Hemolymph SHBP (hJHBP) was partially purified from last instar larvae of Bombyx zori by gel filtration and their optimal reaction conditions of dextrin coated charcoal binding assay were determined. Dissociation constant (KD) of hJHBP for JH III was calculated to be 1.45 $\times$ 10-7 M at $4^{\circ}C.$ The molecular weight of hJHBP was estimated to be 30 kDa by gel filtration on a calibrated Sephadex G-100 column and 33 kDa by SDS-PAGE. These results indicate that hSHBP consists of a single polvpeptide chain. Isoelectric point of hJHBP was found to be pH 5.1 and 19 of the first 20 amino acid residues were determined from N-terminus of purified hJHBP.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.367-373
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• 2013

The ruthenium(II) ferrocenyl heterocyclic thiosemicarbazone complexes of the type $[RuCl(CO)(EPh_3)]_2L$ (where E = P/As; L = binucleating monobasic tridendate thiosemicarbazone ligand) have been investigated. Strutural features were determined by analytical and spectral techniques. Binding of these complexes with CT-DNA by absorption spectral study indicates that the ruthenium(II) complexes form adducts with DNA and has intrinsic binding constant in the range of $3.3{\times}10^4-1.2{\times}10^5M^{-1}$. The complexes exhibit a remarkable DNA cleavage activity with CT-DNA in the presence of hydrogen oxide and the cleavage activity depends on dosage.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.68-72
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• 1983

The $pK_{a}$ of $-NH_{3}^{+}$ group of chitosan in water was 6.2, while that of D-glucosamine-HCl, monomer of chitosan, was found to be 7.8. The difference of $pK_{a}$ values between chitosan and D-glucosamine was attributed to the strong electrostatic interaction between $-NH_{3}^{+}$ groups in chitosan. The apparent binding constant of $Cu^{2+}$ to D-glucosamine was estimated to be $1{\times}10^{4}$. For chitosan, no significant binding of $Cu^{2+}$ to the polymer was observed when pH < 5, but strong cooperative binding was observed near pH 5.1. The mechanism of such cooperativity was proposcd. Chitosan in solution exhibited typical polyelectrolytic behaviors: viscosity increases with increased amount of charged group, and decreases with addition of salt. The concentration dependence of viscosity was measured, and the Huggins parameters and intrinsic viscosity were calculated at various ionic strength. The results were interpreted in terms of molecular properties of the chitosan molecule.