• The Korean Journal of Physiology
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• 제28권1호
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• pp.91-97
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• 1994

In order to produce a specific bombesin antiserum far very sensitive radioimmunoassay, synthetic $[lys^3]-bombesin$ conjugated to bovine serum albumin was subcutaneously injected into guinea pigs. The conjugation was performed using either carbodiimide or gIutaraldehyde as a coupling agent. The antisera were characterized by analysis of Scatchard and Sips plots. The antiserum LBE 2G/2 raised by repeat injection of the immunogen conjugated with carbodiimide showed the titer of 1 : 188,000, very low cross-reactivity to bombesin-like peptides except bombesin, with high affinity constant $(1.64{\times}10^{11}\;M^{-1})$ and high heterogeneity index (0.91). The antiserum LBG 1G/2 produced by repeat injection of the immunogen conjugated with glutaraldehyde possessed the titer of 1 : 43,000, high cross-reactivity to some bombesin-like peptides, high affinity constant $(1.19{\times}10^{11}\;M^{-1})$ and high heterogeneity index (0.79). These results indicate that the antiserum LBE 2G/2 is specific only to bombesin and that the antiserum LBG IG/2 binds to some bombesin-like peptides such as alytesin, gastrin releasing peptide and neuromedin C. The antiserum LBE 2G/2 is sufficient for the very sensitive radioimmunoassay of bombesin.

• Journal of Ginseng Research
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• 제26권4호
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• pp.187-190
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• 2002

Crude synaptic membrane fractions from the frontal cortex, striatum, brain stem and whole brain of rat were prepared to assay the effects of ginseng total saponin (GTS) on [$^3$H]DAGO bindings of the opioid $\mu$-receptors. Scatchard plots analysis binding data demonstrated that GTS (0.1 mg/ml) decreased the affinity of specific [$^3$H]DAGO bindings without changes in B$\_$max/ in the frontal cortex and striatum. On the other hand, GTS did not affect the [$^3$H]DAGO bindings iii the brain stem and whole brain. These results suggest that the regulation of [$^3$H]DAGO bindings by GTS may play roles in the change of the pharmacological responses of $\mu$-opioids.

• BMB Reports
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• 제29권6호
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• pp.525-529
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• 1996

Ligand binding properties of muscarinic acetylcholine receptors (mAChRs) in the nematode Caenorhabditis elegans (C. elegans) were characterized by using filtration binding assays. Scatchard analysis using $[^{3}H]N-methylscopolamine$ ($[^{3}H]NMS$) showed that the dissociation constant ($K_d$) and the maximum binding value ($B_{max}$) were $3.3{\pm}0.8{\times}10^{10}$ M and $9.0{\pm}1.1$ fmol/mg protein, respectively. Binding competition experiments indicated that the affinities of C. elegans mAChRs to atropine, scopolamine, and oxotremorine were similar to those of mammalian mAChRs. Pirenzepine binding experiments revealed that the binding pattern of mAChRs in C. elegans closely resembled that of mAChRs in rat brain, suggesting that the receptors consist primarily of Ml subtype. The affinity of mAChRs for oxotrernorine was significantly affected by guanylylimidodiphosphate (Gpp(NH)p), a non hydrolyzable GTP analog, suggesting that mAChRs in C. elegans might be coupled to G proteins. The data presented here indicate the possibility that C. elegans provides a living animal model to study the action mode of the muscarinic cholinergic system.

• Clinical and Experimental Reproductive Medicine
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• 제16권2호
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• pp.131-138
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• 1989

The present study was designed to develop a new method for the determination of estrogen receptor in porcine uterus using frozen sections. Cryostat sections were incubated with $^3H$-estradiol($^3H$-$E_2$) in the presence or absence of diethylstilbestrol(DES) and the radioactivity of 3H-E2 bound to estrogen receptor(ER) was detected. The level of specific estrogen receptor was determined by Scatchard analysis. The highest ratio of specific binding against total binding was achieved in 3 sec. tions(5mm x 5mm) which was corresponded to lOO${\mu}$/ml protein concentration. Optimal binding was obtained during incubation with $^3H$-$E_2$ for 30 minutes at 23$^{\circ}C$ after treatment of sections with acetone for 20 seconds. Three time-washing of sections was proved to be appropriate for the removal of unbound 3H-E2. 200-fold molar excess of DES was substituted for the binding of $^3H$-$E_2$ to ER sufficiently(binding efficiency of 54.8%). ER was saturated with 4nM of $^3H$-$E_2$ and its dissociation constant was 0.1nM. ER assay using frozen sections(Histological radioreceptor assay, HRRA) was significantly correlated with radioreceptor assay for estradiol(RRA, 0.976 , p

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.523-528
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• 1997

Peripheral benzodiazepine receptor(PBR) has been indentified in various peripheral tissues including kidney. The physiological and pharmacological functions of PBR are still uncertain, althought it has been suggested that these are associated with the regulation of stress/anxiety response. Diazepam progeny, which were exposed to diazepam perinatally, was reported to be an animal model of chronic anxiety. However, PBR in the diazepam progenies are not known yet. In the present study, therefore, we examined the changes of PBR in the stress/anxiety response. Dams of rats were given injection of diazepam or vehicle during puerperium. Diazepam progenies showed increased level of anxiety on the performance of elevated plus maze, and increased Bmax of PBR. Saturation experiments followed by scatchard analysis of the results showed that the increase in the density of PBR and the affinity of the PBR remained unchanged. Forced swim stress increased anxiety on the plus maze in both groups of rats. In contrast to control, diazepam progenies did not show further upregulation of renal PBR immediately after swimming stress, but still higher than control. From the above results, it may be concluded that upregulation of renal PBR is associated with chronic anxiety as well as stress-induced response.

• 약학회지
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• 제40권6호
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• pp.734-738
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• 1996

The development of the alpha2 isoform of (Na,K)ATPase which is high affinity ouabain receptors was studied in the differentiating nonfusing muscle cell line BC3H-1. T he differentiation process of BC3H-1 cell line was confirmed by 2-dexy-D-[$^3$H] glucose uptake experiment and the quantity of the expression of ${\alpha}_2$ isoform was measured using a whole cell [$^3$H] ouabain-binding assay. Undifferentiated growing BC3H-1 cells, myoblasts, exhibited low levels of insulin-stimulated glucose uptake and [$^3$H] ouabain-binding sites. In contrast, differentiated BC3H-1 cells, myocytes, had a 5.6-fold increase in insulin-stimulated glucose uptake and 5-fold increase in [$^3$H] ouabain-binding sites. Scatchard analysis showed that myocytes developed more [$^3$H] ouabain-binding sites than myoblasts vath a dissociation constant (kd) of 6${\times}10^{-8}$M and capacity of 6.l${\times}10^{-5}$ sites/cell. Therefore. it seems that myoblasts express low levels of ${\alpha}_2$ subunit and probably the majority of ${\alpha}_1$ subunit, whereas myocytes express high levels of ${\alpha}_2$ isoform. The results indicate that the expression of ${\alpha}_2$ isoform is developmentally regulated during differentiation and that BC3H-1 culture system provides an excellent model for the study of differentiation and mechanism of (Na,K)ATPase action in muscle which requires electrical excitability.

• 약학회지
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• 제36권3호
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• pp.220-229
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• 1992

The muscarinic acetylcholine receptors of the dog unpregant uterus were characterized using $[^3H]quinuclidinyl$ benzilate(QNB) as a radioligand and the binding of muscarinic receptor agonists and antagonists in the uterus was compared to that in the urinary bladder which contains almost exclusively the M2 receptors in order to determine the receptor subtypes in the uterus. $[^3H]QNB$ binding to uterus and bladder was rapid, saturable and reversible. Scatchard analysis of the saturation data gave linear plots and the Hill coefficients were close to unit, which indicated that each preparation contained a single population of specific binding sites for $[^3H]QNB$. The KD values(120 pM) for QNB were almost identical in both organs, whereas the $B_{max}$ value of 256 fmol/mg protein in the uterus was significantly different from that of 563 fmol/mg protein in the bladder. Muscarinic agonists and antagonists inhibited in a competitive manner the $[^3H]QNB$ binding to the same extent in both organs. The competition binding studies using antagonists(atropine and pirenzepine) exhibited a single binding site and this site had a low affinity for pirenzepine with the Ki value of about 330 nM. However, high and low affinity binding sites were observed with carbachol, methacholine and oxotremorine. These binding studies with agonists and antagonists did not show any differences in drug affinities between uterus and bladder. These results indicate that the muscarinic receptors in the uterus are M2 receptors which have a low affinity for pirenzepine.

• Biomolecules & Therapeutics
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• 제5권4호
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• pp.325-330
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• 1997

Methanol extract of G. elata inhibited the binding of [/sup 3/H]Rol5-1788, a selective benzodiazepine receptor antagonest, to benzodiazepine receptor of rat cortices. Saturation experiments followed by Scatchard analysis of the results showed that the inhibition of [sub 3/H]Ro15-1788 binding by G. dlata. appeared to be com-petitive. These competitive inhibiton of the butanol fraction was observed to be higher than the methanol extract. Methanol extract of G. efara inhibited a [sub 3/H]flunitrazepam, a selective benzodiazepine receptor agonist, binding to benzodiazepine receptor. GABA significantly enhanced the inhibition of [/sub 3/H]flunitrazepam binding by G. elata, and these "positive GABA shift" supported the strong possibility of agonestic activity to benzodiazepine receptor Butanol fraction was observed to be higher than crude extract by methanol in an agonistic activity to benzodiazepine receptor, furthermore enhanced the binding of [sub 3/H]SR95531 to GABA receptor. Butanol fraction of G. elata significantly diminished the pentylenetetrazole-induced lethality of mice. From these results, it can be concluded that substance or substances with neurochemical properties characteri- stic of a benzodiazepine receptor agonist may be important components, and contribute to the anticonvulsant property of G. elata.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1023-1031
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• 2017

The conformational change of cellular prion protein ($PrP^C$) to its misfolded counterpart, termed $PrP^{Sc}$, is mediated by a hypothesized cellular cofactor. This cofactor is believed to interact directly with certain amino acid residues of $PrP^C$. When these are mutated into cationic amino acid residues, $PrP^{Sc}$ formation and prion replication halt in a dominant negative (DN) manner, presumably due to strong binding of the cofactor to mutated $PrP^C$, designated as DN PrP mutants. Previous studies demonstrated that plasminogen and its kringle domains bind to PrP and accelerate $PrP^{Sc}$ generation. In this study, in vitro binding analysis of kringle domains of plasminogen to Q167R DN mutant PrP (PrPQ167R) was performed in parallel with the wild type (WT) and Q218K DN mutant PrP (PrPQ218K). The binding affinity of PrPQ167R was higher than that of WT PrP, but lower than that of PrPQ218K. Scatchard analysis further indicated that, like PrPQ218K and WT PrP, PrPQ167R interaction with plasminogen occurred at multiple sites, suggesting cooperativity in this interaction. Competitive binding analysis using $\small{L}$-lysine or $\small{L}$-arginine confirmed the increase of the specificity and binding affinity of the interaction as PrP acquired DN mutations. Circular dichroism spectroscopy demonstrated that the recombinant PrPs used in this study retained the ${\alpha}$-helix-rich structure. The ${\alpha}$-helix unfolding study revealed similar conformational stability for WT and DN-mutated PrPs. This study provides an additional piece of biochemical evidence concerning the interaction of plasminogen with DN mutant PrPs.

• 대한의생명과학회지
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• 제5권1호
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• pp.1-10
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• 1999

본 연구에서는 혈장이나 양수에 있는 $\alpha$-fetoprotein (AFP)을 인식 할 수 있는 모노클로날 항체를 제조하고, 모노클로날 항체를 이용한 효소면역분석법을 개발하고자 하였다. 양수로부터 얻은 AFP를 쥐에 주사한 후 비장을 분리하여 종양세포 (Sp2/O-Ag-14)와 융합하였고, 하이브리도마 기술을 이용하여 모노클로날 항체를 제조하였다. 모노클로날 항체를 클로닝하였으며, 생성된 항체를 MabF22로 명명하였고, IgG1 중사슬과 k 경사슬의 isotype을 나타냈다. 또한 immunoblotting 방법과 ELISA로 특이도를 조사한 결과 모노클로날 항체는 AFP와만 반응하였고, 결합 친화상수는 0.8$\times$$10^{-10}$M이었다. 두 종류의 효소면역분석법 -경쟁적 또는 비경쟁적 분석 -을 이용하여 항체의 효용성을 조사하였으며, 두 방법 모두 AFP와 농도에 비례하여 반응하였다. 따라서 본 연구에서 생산된 모노클로날 항체는 연구목적으로 뿐만 아니라 AFP 농도를 측정하기 위한 면역진단시약의 개발에도 유용할 것으로 생각된다.