• Asian-Australasian Journal of Animal Sciences
• /
• 제10권2호
• /
• pp.233-239
• /
• 1997

A mammary epithelial cell line (MAC-T) established as a model for lactation was utilized to identify and characterize effects of various hormones upon insulin-like growth factor binding protein secretion. Ligand and immunoblot analyses of conditioned media indicated that insulin-like growth factor binding protein-2 was secreted by MAC-T cells. Insulin-like growth factor-I stimulated insulin-like growth factor binding protein-2 secretion in a dose-dependent manner, but prolactin and bovine somatotropin did not alter insulin-like growth factor binding protein-2 secretion. Insulin increased and cortisol decreased insulin-like growth factor binding protein-2 secretion. Effects of insulin-like growth factor-I on insulin-like growth factor binding protein-2 secretion support previous studies using primary cultures of bovine mammary cells and bovine fibroblasts. Effects of cortisol and insulin on insulin-like growth factor binding protein-2 secretion may be explained by changes in protein synthesis. In addition, supraphysiological doses of insulin can cross-react with the insulin-like growth factor-I receptor and stimulate insulin-like growth factor binding protein-2 secretion. MAC-T cells provide a model system to study mechanisms that regulate local insulin-like growth factor-I bioactivity.

• BMB Reports
• /
• 제33권5호
• /
• pp.391-395
• /
• 2000

Calexcitin, a calcium-binding protein, was previously cloned and functionally characterized in the squid Loligo pealei. We now report the cloning of a second form of Calexcitin, Calexcitin-2, found in the squid Todarodes pacificus optic lobe. Calexcitin-2 has a significantly different carboxyl terminal region than Calexcitin-1. It lacks the CAAX motif, which is a farnesylation site. The amino acid sequence of Calexcitin-2 shows an 84% identity with Calexcitin-1 and also displays a strong cross immunoreactivity. Western blotting shows that Calexcitin-2 was expressed exclusively in the optic lobe region of squid, but not in other body organs. Regardless of its lack of conserved regions for GTP-binding, Calexcitin-2 shows moderately low affinity GTP-binding and also shows dramatic conformational change induced by GTP-binding. Three possible GTP-binding region mutations, K142A, D144A, and K157A, did not change the G TP binding affinity. This raises the possibility that Calexcitin-2 may have a novel GTP-binding motif.

• Journal of Microbiology and Biotechnology
• /
• 제17권7호
• /
• pp.1120-1126
• /
• 2007

This study was performed to screen probiotic bifidobacteria for their ability to bind and neutralize lipopolysaccharides (LPS) from Escherichia coli and to verify the relationship between LPS-binding ability, cell surface hydrophobicity (CSH), and inhibition of LPS-induced interleukin-8 (IL-8) secretion by HT-29 cells of the various bifidobacterial strains. Ninety bifidobacteria isolates from human feces were assessed for their ability to bind fluorescein isothiocyanate (FITC)-labeled LPS from E. coli. Isolates showing 30-60% binding were designated LPS-high binding (LPS-H) and those with less than 15% binding were designated LPS-low binding (LPS-L). The CSH, autoaggregation (AA), and inhibition of LPS-induced IL-8 release from HT-29 cells of the LPS-H and LPS-L groups were evaluated. Five bifidobacteria strains showed high levels of LPS binding, CSH, AA, and inhibition of IL-8 release. However, statistically significant correlations between LPS binding, CSH, AA, and reduction of IL-8 release were not found. Although we could isolate bifidobacteria with high LPS-binding ability, CSH, AA, and inhibition of IL-8 release, each characteristic should be considered as strain dependent. Bifidobacteria with high LPS binding and inhibition of IL-8 release may be good agents for preventing inflammation by neutralizing Gram-negative endotoxins and improving intestinal health.

• 약학회지
• /
• 제26권4호
• /
• pp.223-229
• /
• 1982

Uremia is associated with defective protein binding of weakly acidic drugs, whereas the protein binding of basic drugs tends to be normal. The exact chemical nature of compound(s) and mechanism for these changes as yet is unknown, and has not been defined. Organic solvent extraction of pooled normal human urine following hydrolysis by hydrochloric acid produced an extract, which when added to normal human serum, was capable of inducing binding defects similar to those in uremia. Binding defects were observed with the weakly acidic drugs such as nafcillin, salicylate, sulfamethoxazole and phenytoin while the binding of the basic drugs such as trimethoprim and quinidine were unaffected. The binding defects induced by the hydrolyzed urine extract could readily be corrected by same organic solvent extraction of acidified serum and the defects could be transferred to the normal human serum using the organic solvent layer at the physiologic pH (7.4). Followed by reacidification ind extraction of the binding defects induced serum with the same solvent, separated several fractions were obtained on thin-layer chromatography. One of these fractions could reinduce the binding defects and this factor(s) is apparently weakly acidic compounds and tightly bound to serum at physiologic pH, but extractable at acidic pH, and its molecular weight range is approximately 500 or less similar to those seen in uremia. These findings strongly support the hypothesis that the drug binding defect in uremia is due to the accumulation of endogenous metabolic products which arc normally excreted by the kidneys but accumulate in renal failure.

• Archives of Pharmacal Research
• /
• 제20권6호
• /
• pp.579-585
• /
• 1997

To gain further insight into the mechanism of action of antiestrogens, we examined the interaction of antiestrogen with the estrogen receptor system and with estrogen- noncompetable antiestrogen binding sites. In addition to binding directly to the estrogen receptor, antiestrogens can be found associated with binding sites that are distinct from the estrogen receptor. In contrast to the restriction of estrogen receptors to estrogen target cells, such as those of uterus and mammary glands, antiestrogen binding sites are present in equal amounts in estrogen receptor-positive and -negative human breast cancer cell lines, such as MCF-7, T47D, and MDA-MB-231 that differ markedly in their sensitivity to antiestrogens. In order to gain greater insight into the role of these antiestrogen binding sites in the action of antiestrogens, we have examined the biopotency of different antiestrogens for the antiestrogen binding sites and that is CI628 > tamoxifen > trans-hydroxy tamoxifen > CI628M > H1285 > LY117018. This order of affinities does not parallel the affinity of these compounds for the estrogen receptor nor the potency of these compounds as antiestrogens. Indeed, compounds with high affinity for the estrogen receptor and greatest antiestrogenic potency have low affinities for these antiestrogen binding sites. Antiestrogenic potency correlates best with estrogen receptor affinity and not with affinity for antiestrogen binding sites. In summary, our findings suggested that interaction with the estrogen receptor is most likely the mechanism through which antiestrogens evoke their growth inhibitory effects.

• 대한약리학회지
• /
• 제18권2호
• /
• pp.33-44
• /
• 1982

전해질농도(電解質濃度)를 달리하고 morphine, naloxone 또는 morphine+naloxone을 가(加)하거나 가(加)하지 않은 modified Krebs-Henseleit bicarbonate buffer용액(溶液)에 흰쥐의 뇌절편(腦切片)을 incubate하여 저온처리(低溫處理)와 media내(內) 전해질조성(電解質組成)이 $(^3H)-morphine$의 saturable binding에 미치는 영향(影響)을 관찰(觀察)하여 다음과 같은 성적(成績)을 얻었다. 1) 저온처리(低溫處理)는 $(^3H)-morphine$의 saturable binding을 현저(顯著)히 증가(增加)시켰고, maximal saturable binding은 증가(增加)시키나 $K_D$치(値)에는 영향(影響)을 미치지 못하였다. 2) 저온처리시(低溫處理時) media내 morphine과 naloxone은 $(^3H)-morphine$ 의 maximal saturable binding 과 $K_D$치(値)를 증가(增加) 시켰다. 3) 저온처리시(低溫處理時) media내(內) $K^+$감소(減少), $Mg^{++}$제거 또는$Mn^{++}$첨가(添加)는 $(^3H)-morphine$의 saturable binding을 현저(顯著)히 증가(增加)시켰고, $Na^+$감소(減少), $Ca^{++}$증가(增加)는 saturable binding에 영향(影響)을 미치지 못하였다. 4) 저온처리시(低溫處理時) media내(內) morphine에 의한 $(^3H)-morphine$의 saturable binding증가(增加)는 media내(內) $Na^+$감소(減少), $K^+$감소(減少), $Mg^{++}$제거 또는 $Mn^{++}$첨가(添加)로는 영향(影響) 받지 않았으나 $Ca^{++}$증가(增加)로 억제(抑制)되었고, media내(內) naloxone에 의한 saturable binding증가(增加)는 $Mn^{++}$첨가(添加)는 영향(影響)받지 않았으나 media내(內) $Na^+$감소(減少), $K^+$감소(減少), $Ca^{++}$증가(增加) 또는 $Mg^{++}$제거로 억제(抑制)되었다. 이상(以上) 실험성적(實驗成績)은 저온처리(低溫處理) 및 저온처리시(低溫處理時) media내(內) morphine 또는 naloxone이 opiate수용체(受容體)의 양적(量的)인 변동(變動)과 또는 친화력(親和力)의 변동(變動)을 유발(誘發)하며, media내(內) 전해질조성(電解質組成)이 이들 변동(變動)에 영향(影響)을 미침을 시사(示唆)한다.

• Archives of Pharmacal Research
• /
• 제14권3호
• /
• pp.231-236
• /
• 1991

The high affinity binding sites for angiotensin II were solubilized from rat liver membranes by treatment with CHAPS. The binding protein was also partially purified by angiotensin III inhibitor-coupled Affi-gel affinity chromatography. Binding to the intact membrances as well as to the solubilized preparation was specific and saturable. According to the Scatchard plot, the membrane preparations exhibited a single class of high affinity binding sites with a Kd OF 0.71 nM. The solubilized preparation also showed the presence of a single class of bindings sites with less affinity (Kd of 14 nM). Meanwhile the competition studies using angiotensin II analogues represented two separate binding sites for angiotensin II and single binding site for antagonist. These latter findings were correlated to the results provided by Garrison's research group. More works are needed to clarify this discrepancy.

• KSBB Journal
• /
• 제14권3호
• /
• pp.273-278
• /
• 1999

The molecularly imprinted polymers(MIPs) synthesized at various polymerization conditions were examined as ibuprofen receptors in terms of binding characteristics. The 4-vinylpyridine polymers had 1.2 times higher adsorption capability for (S)-(+)-ibuprofen than the methacrylic acid polymers. The methacrylic acid polymers synthesized by UV radiation had 1.9 times higher selectivity for (S)-(+)-ibuprofen compared to those by thermal initiation. Effects of various solvents for binding were also examined in this research. According to the Scatchard analysis, the (S)-(+)-ibuprofen artificial receptors had two different kinds of binding sites for (S)-(+)-ibuprofen while having only single kind of binding site for ketoprofen. The binding sites of (S)-(+)-ibuprofen, n were calculated as 4.3~4.9 $\mu$mol/g and the dissociation constants, $K_D$ were 0.68 mM for the specific binding.

• 한국동물학회지
• /
• 제34권2호
• /
• pp.196-202
• /
• 1991

매미나방 종령유층 혈림프내에 존재하는 JHBP을 Dextran Coated Charcoal (DCC)binding assay와 gel filtration에 의해서 확인하였고, JHBP의 pI값은 5.3으로 밝혀졌다. JHBP의 정저는 혈림프단백질을 먼저 PEG로 침전시킨 후 ion exchange chromatography와 gel filtration 방법을 통하여 행하였다. 정체된 fraction의 JH에 대한 binding activity는 [3H] JH-III의 radioactivity 측정과 DCC binding assay를 통해 확인하였고, 정체된 단백질의 순수도는 각 정체단계에 따라 전지영동을 하여 확인하였다.

• Computers and Concrete
• /
• 제13권6호
• /
• pp.695-707
• /
• 2014

This study investigated the chloride binding isotherms of various cement types, especially the contributions of C-S-H and AFm hydrates to the chloride binding isotherms were determined. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low-heat Portland cement (LHC) were used. The total chloride contents and free chloride contents were analyzed by ASTM. The contents of C-S-H, AFm hydrates and Friedel's salt were determined by X-ray diffraction Rietveld (XRD Rietveld) analysis. The results showed that OPC had the highest chloride binding capacity, and, LHC had the lowest binding capacity of chloride ions. MC and RHC had very similar capacities to bind chloride ions. Experimental equations which distinguish the chemically bound chloride and physically bound chloride were formulated to determine amounts of the bound chloride basing on chloride binding capacity of hydrates.