• Archives of Pharmacal Research
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• 제27권9호
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• pp.978-983
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• 2004

The effects of glycyrrhizic acid (GLZ) on protein binding of diltiazem, verapamil, and nifedipine were investigated. Protein binding studies (human serum, human serum albumin (HSA) and (X1-acid glycoprotein (AAG)) were conducted using the equilibrium dialysis method with and without addition of GLZ. The binding parameters, such as the number of moles of bound drug per mole of protein, the number of binding sites per protein molecule, and the association con-stant, were estimated using the Scatchard plot. The serum binding of nifedipine, verapamil, and diltiazem was displaced with addition of GLZ, and the decreases of Ks for serum were observed. GLZ decreased the association constants of three drugs for HSA and AAG, while the binding capacity remained similar with addition of GLZ. Although the characteristics of interaction were not clear, GLZ seemed to mainly affect HSA binding of nifedipine rather than AAG binding, while GLZ seemed to affect both AAG- and HSA-bindings of verapamil and dilt-iazem resulting in a serum binding displacement.

• Journal of Pharmaceutical Investigation
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• 제19권1호
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• pp.15-20
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• 1989

The displacement of protein bound sulfonamides (sulfisoxazole, sulfamethoxazole, sulfisomidine) by furosemide was investigated in bovine serum albumin by equilibrium dialysis method. Furosemide $(2{\times}10^{-4}M)$ in bovine serum albumin ($7.24{\times}10^{-5}$, $1.45{\times}10^{-4}$, $2.89{\times}10^{-4}M$). Sulfisoxa캐1e and furosemide were bound reversibly to bovine serum albumin and competitive for the same binding sites when administered together. Consequently, dosage regimen of sulfisoxazole should be adjusted carefully when sulfisoxazole is administered along with furosemide.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.143-151
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• 1998

Protein -surfactant interactions have been investigate by measuring ζ-potential of $\beta$-lactoglobulin-coated emulsion droplets and $\beta$-lactoglobulin in solution in the rpesenceof surfactant, with particular emphasis on the effect of protein heat treatment(7$0^{\circ}C$, 30min). When ionic surfactant (SDS or DATEM) is added to the protein solution, the ζ-potential of the mixture is found to increase with increasing surfactant concentration, indicating surfactant binding to the protein molecules. For heat-denatured protein,it has been observed that the ζ-potential tends to be lower than that of the native protein. The effect of surfactant on emulsions is rather complicated .With SDS, small amounts of surfactant addition induce a sharp increase in zeta potential arising from the specific interaction of surfactant with protein. With further surfacant addition, there is a gradual reductio in the ζ-potential, presumably caused by the displacement of adsorped protein (and protein-surfactant complex) from the emulsion droplet surfac by the excess of SDS molecules. At even higher surfactant concentrations, the measured zeta potential appears to increase slightly, possibly due to the formation of a surfactant measured zeta potential appears to increase slightly, possibly due to the formation of surfactant micellar structure at the oil droplet surface. This behaviour contrastswith the results of the corresponding systems containing the anionic emulsifier DATEM, in which the ζ-potential of the system is found to increase continuously with R, particularly at very low surfactant concentration. Overall, such behaviour is consisten with a combination of complexation and competitive displacement between surfactant and protein occurring at the oil-water interface. In addition, it has also been found that above the CMC, there is a time-dependent increase in the negative ζ-potential of emulsion droplets in solutions of SDS, possibly due to the solublization of oil droplets into surfactant micelles in the aqueous bulk phase.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.212-216
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• 2015

Oseltamivir, also known as Tamifu, is an inhibitor of neuraminidase protein which plays an essential role in proliferation and replication of influenza virus. Binding to the active site of neuraminidase, the oseltamivir prevents the protein from enzyme reaction. Conformational change of the protein(neuraminidase) should be accompanied by the enzyme reaction, but the drug inhibits the protein to deform. In this study, we examine the influence of oseltamivir on protein's conformational change in the structural and mechanical point of view. Finite element analysis of the protein can be an useful approach to investigate the influence of oseltamivir on the deformation of a protein. We suggest the finite element based protein model, and then perform the linear static analysis with the displacement loading condition based on the first two largest motion which can be obtained from the normal mode analysis. The results show that it takes more energy to change shape of the protein with an oseltamivir attached than the protein without an oseltamivir.

• Archives of Pharmacal Research
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• 제4권2호
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• pp.99-107
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• 1981

To investigate the protein binding characteristics of ibuprofenlysine, the effects of drub conentration, pH, ionic strength and protein concentration on the binding of drug to protein concentration on the binding of drug to protein were studied by fluorescence probe method. The conformational change of protein was investigated by circular dichroism (CD) measurement. As the concentration of drug increases, the association constant decreases. These may be due to complex formation of the probe and drug, or the interaction of the protein-probe complex and drug. The association constant for ibuprofenlysine increased with increasing protein concentration. These finding suggest a sharing of one ibuprofenlysine molecule by more than one protein molecule in the binding. The binding between ibuprofenlysine and protein was dependent on pH and ionic strength. It seems that both hydrophobic binding and some electrostatic forces are involved in the binding of ibuprofenlysing to protein.

• Journal of Pharmaceutical Investigation
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• 제15권1호
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• pp.1-7
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• 1985

Previous studies show that the free (unbound) fraction of disopyramide in human serum is drug concentration dependent~ at corresponding serum disopyramide concentrations that are achieved clinically. $^1^{\sim}^3^)\;Moreover$, disopyramide free fraction values vary several fold at any given drug concentration in human serum and tend to decrease as serum cocentrations of alpha-I-acid glycoprotein(AAG) incrase.$^4^)$ A recent $study^5^)$ demonstrates that the free fraction of disopyramide inhuman serum increases almost 2-fold following the addition of $14.4{\mu}M/L$ mono-N-dealkyldisopyramide. These studies and others. $^6^),\;^7^)$ prompted the present investigation to characterize the protein binding of disopyramide in human serum and solutions of AAG in the presence of mono-N-dealkyldisopyramide (a major metabolite of, disopyramide) and to determine the utility of using commercially available alpha-I-acid glycoprotein for drug protein binding displacement studies. Because many basic and acidic compounds are known to bind to alpha-I-acid $glycoprotein^8^)$ the present study. was performed to determine whteher commercially available AAG would provide a convenient protein source for such binding studies.

• 한국축산식품학회지
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• 제44권6호
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• pp.1389-1402
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• 2024

The demand for healthy ingredients in food products including ice cream, is continuously increasing. The potential of a combination of milk polar lipids (MPL) and casein hydrolysate (CH) to replace synthetic emulsifiers such as diacetyl tartaric acid esters of monoglycerides (DATEM), in ice cream production was investigated. Changes in particle size, emulsion stability, and interfacial tension of model emulsions (milk protein, casein:whey=8:2, w/v) were analyzed after the addition of MPL, CH, and their combination (MPL+CH). The use of MPL+CH reduced interfacial tension and increased α_s- and β-casein displacement from the surface of cream layers compared to the addition of MPL alone. The addition of MPL+CH improved ice cream overrun to levels comparable to those of control ice cream containing DATEM (0.3%, w/v), without adversely affecting melt rate or microstructure. Confocal laser scanning microscopy revealed that ice cream prepared with MPL+CH formed a thick protein and coalesced fat layer on the surface of air cells that might help enhance overrun. These findings suggest that the combination of MPL (0.3%, w/v) and CH (0.03%, w/v) can be used as a potential emulsifier alternative to replace chemically synthesized emulsifiers such as DATEM.

• 대한치과보철학회지
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• 제14권1호
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• pp.55-65
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• 1976

The influences of the mandibular displacement and valium administration on the muscular activity were observed by spectrophotometric analysis of glycogen, glucose, G-6-P, lactate, pyruvate, ATP, phosphocreatine ana protein. Experimental animals were divided into three groups; the first was the mandibular displacement group, the second was valium administered group and the third was the mandibular displacement and valium admministered group. In mandibular displacement group, the high inclined plane with a gap of 2.5mm to 3.0mm between the upper and lower incisors was created by setting the silver crowns on the lower incisors. By creating such a high inclined plane, the bite was opened and the mandible was dispalced posteriorly. In valium administered group, 5mg/kg body weight of valium was administered intraperitoneally every day until the animal was sacrificed. Results were as follows: I) The body weight of all experimental rats was decreased in the beginning of experimental periods. The body weight of the mandibular displacement group showed the similar increasing rate as the control group from 15 days of experimental period. 2) The superficial masseter muscles of the mandibular displacement group appeared to be decreased it's functional activity at 36hrs, 60hrs and 96hrs of experimental periods as revealed by the decrease of various metabolites studied in this experiment. From 96hrs of experimental periods, the contents of those metabolites tended to increase up to the control level. 3) The superficial masseter muscle of 2nd group showed the decreased value of all metabolites at until 60hrs and the values were recovered to almost the same as the control at 168hrs. 4) Glycogen and G-6-P contents induced by mandibular displacement plus valium administration, showed longer duration of the decreased value than 1st group. And the decrease of glucose and pyruvate contents induced by mandibular displacement at 36hrs and 60hrs of experimental periods was enhanced by valium administration. However, the contents of lactate in 3rd group were decreased continuously until the end of experiment.

• 폴리머
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• 제36권3호
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• pp.338-343
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• 2012

콘텍트렌즈용 하이드로젤의 계면 특성의 이해를 위해 단백질 흡착 현상을 열역학을 바탕으로 연구하였다. 다른 습윤성을 갖는 $1{\times}1mm^2$ 크기의 하이드로젤을 알부민(bovine serum albumin, BSA)용액에 1시간 동안 침지시킨 후 남아있는 BSA 용액의 농도를 Bradford assay로 정량하였다. 모든 하이드로젤로의 단백질 흡착량은 단백질 농도가 증가함에 따라 계면 흡착량이 증가하며 Langmuir 곡선의 형태를 보였다. 또한 계면과 용액내의 단백질 농도비($P$), 계산된 흡착 Gibbs free energy는 하이드로젤 재료의 친수성도가 증가함에 따라 증가하였다. 표면에너지와 단백질 흡착량 상관관계를 이해하여 콘택트렌즈 재질로의 단백질 흡착현상의 물리화학적 해석이 가능함을 알 수 있었다.

• Archives of Pharmacal Research
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• 제10권1호
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• pp.29-35
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• 1987

The effect of drug addition on the bovine serum albumin (BSA)-edible dye complex was studied by spectrophotometric method. The edible dyes tested were amranth, erythrosine, tatrazine and sunset yellow. The moles of bound dye per protein mole and free energies for edible dyes bounded were determined at pH 7.4. The values of free energy change by the addition of drughs to BSA-edible dye were ranged fro -6, 260 to 08030 cal/mole. In the wide range of edible dye concentration (0.3-$7{\times}10^{-5}$$^{-5}$ M), acetylsalicylic acid (ASA) showed pattern of displacement different from that of dye. It was assumed that ASA has different binding mechanisms from edible dye.