共查询到20条相似文献,搜索用时 15 毫秒
1.
利用荧光技术研究了在生理酸度条件下,二氢氯噻与牛血清白蛋白相互作用,发现二氢氯噻对牛血清白蛋白有较强的荧光猝灭作用,用Stern-Volmer和Line weaver-Burk方程处理荧光猝灭数据,得到了反应的结合常数、结合热力学性质等参数。根据热力学参数确定了该药物与血清白蛋白之间的作用力类型,在此基础上依据福斯特F rster非辐射能量转移理论探讨了二氢氯噻与BSA相互结合时其供体-受体间的距离。与人血清蛋白[1]比较,牛血清白蛋白与二氢氯噻的结合较弱,体现了二氢氯噻与血清蛋白结合的动物间的差异性。同时考察了中药活性成分和金属离子对结合的影响,结果显示甘草次酸对结合的影响较大,提示同时给药时应该注意它们之间的血清药物相互作用。 相似文献
2.
The interaction of 5-dimethylaminonaphthalene-1-sulfonyl (DNS or dansyl) amino acids with bovine serum albumin (BSA) was investigated by means of fluorescence measurements. Fluorometric titrations revealed that BSA has one high affinity site (binding constant,K
a=105106 M–1), and other sites of lower affinity (K
a=103104 M–1) for the probes. Static excitation and emission spectra, lifetimes, time resolved emission spectra, and anisotropy data indicated that the binding is stabilized mainly through fixation by the high affinity binding site. The binding constant significantly decreased with the increase of the spacer distance between the dansyl and anionic groups of the probe molecule. This observation was explained by considering the change of the electrostatic interaction between the anionic group of the probe and a cationic residue in the vicinity of the site. 相似文献
3.
The interaction of magnolol with bovine serum albumin(BSA) was studied using fluorescence spectroscopy under physiological conditions. The binding constants, K, and the ratio of quantum yields of protein fluorescence for complex and free protein, f, at 298 K, 304 K, and 310 K were obtained; the values were 6.799×105 L mol–1, 5.541×105 L mol–1, and 4.344×105 L mol–1 and 0.17, 0.30, and 0.34, respectively. The standard enthalpy change (H°) and the standard entropy change (S°) were calculated to be –28.53 kJ mol–1 and 15.88 J mol–1 K–1, which indicated that hydrophobic forces played major role in the interaction of magnolol and BSA. The binding average distance between magnolol and BSA (4.32 nm) was obtained on the basis of the theory of Förster energy transfer. 相似文献
4.
溴甲酚绿分光光度法测定牛血清白蛋白 总被引:2,自引:0,他引:2
在pH 3.3的Britton-Robinson (B-R)缓冲溶液中, 对溴甲酚绿(BCG)与牛血清白蛋白(BSA)相互作用的吸收光谱进行了初步研究. 结果表明: BCG与BSA作用在室温下能迅速结合成复合物, 并且随着BSA的浓度增大, 在444 nm处的吸收峰降低, 618 nm处吸收峰升高并红移至628 nm. 在此波长下测定其复合物的吸光度, 其吸光度的增加值(ΔA)与BSA的质量浓度在8~260 μg/mL范围内呈良好的线性关系(r=0.9996), 检出限为4 μg/mL. 该方法应用于鲜奶粉和液态纯牛奶样品中总蛋白的测定, 回收率分别为92.7%, 95.5%, 结果与考马斯亮蓝G250法基本一致. 相似文献
5.
Electrostatic interaction between poly(methyl methacrylate) latex particles with different levels of chitosan modification
and bovine serum albumin (BSA) was investigated. The critical flocculation concentration is in the range 5–15 nmol dm−3 for these latex products toward added BSA. A series of isothermal equilibrium adsorption experiments shows that the adsorption
process is divided into two distinct intervals. Adsorption of BSA on latex particles in intervals I and II is primarily controlled
by charge neutralization and hydrophobic interaction, respectively. Intervals I and II can be reasonably described by an empirical
parabola equation and the Langmuir isotherm model, respectively. The maximum amount of BSA adsorbed per unit weight of polymer
particles was observed at pH ≅ 5. A maximum elution yield of about 80% can be achieved using NaSCN as the elution electrolyte,
and NaSCN is more effective in inducing desorption of BSA from the particle surface than NaCl. The chitosan content has very
little effect on the interaction between latex particles and BSA. By contrast, the influence of the content of 2,2′-azobis(2-amidinopropane)
dihydrochloride, a cationic initiator used in preparing the chitosan-modified latex products, on the BSA adsorption process
is significant.
Received: 26 March 1999 Accepted in revised form: 3 June 1999 相似文献
6.
《Journal of Coordination Chemistry》2012,65(10):1503-1512
The interaction of octacarboxylic metal phthalocyanines (MPc(COOH)8, M =?Al(III) and Co(II) with bovine serum albumin (BSA) has been studied. From the binding isotherm based on spectrophotometric titration, the association constant and a number of ligands per binding site were calculated at 25°C. By using the well studied Hemin chloride (HE), Ibuprofen(IB) and L-tryptophan (TRP) as competitive ligands, the binding sites of AlPc(COOH)8 were found to be on domain I and II of BSA, while on domain I for Co(COOH)8. 相似文献
7.
Rong Min Wang Juan Juan Mao Jing Feng Song Cai Xia Huo Yu Feng He 《中国化学快报》2007,18(11):1416-1418
Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin (BSA),which afforded BSA binding Schiff-base metal complexes (BSA-SalGluM,M=Cu,Co,Ni,Zn).The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE.It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes.The effect of the antioxidant activity was investigated.The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes. 相似文献
8.
《Journal of Coordination Chemistry》2012,65(4):722-739
Some new water-soluble Schiff-base complexes Na2[M(5-SO3-2,3-salpyr)(H2O) n ]?·?2H2O (5-SO3-2,3-salpyr?=?N,N′-bis(5-sulphosalicyliden)-2,3-diaminopyridine and M?=?Zn, Cu, Ni) were synthesized and characterized by elemental analysis, IR, 1H NMR, magnetic susceptibility measurement, thermal analysis, and UV-Vis spectroscopy. The mechanism of binding of Na2[M(5-SO3-2,3-salpyr)(H2O) n ]?·?2H2O with bovine serum albumin (BSA) was investigated by fluorescence spectroscopy. The fluorescence titration revealed that the intrinsic fluorescence of BSA was quenched by Na2[M(5-SO3-2,3-salpyr)], which was rationalized in terms of the static quenching mechanism. The values of the Stern–Volmer constants, quenching rate constants, binding constants, binding sites, and average aggregation number of BSA were determined by this method. Thermodynamic parameters were calculated by the van’t Hoff equation. The data clearly indicate that the binding is entropy driven and enthalpically disfavored. Based on the Förster theory of non-radiative energy transfer, the efficiency of energy transfer, and the distance between the donor (Trp residues) and the acceptor (Na2[M(5-SO3-2,3-salpyr)]) were evaluated. Also the synchronous fluorescence spectra showed that the microenvironment of the tryptophan residues was not changed. Finally, our results indicate that the complexes can bind to BSA and be efficiently transported in the body, which could be helpful for further drug design. 相似文献
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Synthetic materials capable of recognizing proteins are important in separation, biosensors and biomaterials. In this study,
bovine serum albumin-imprinted soft-wet polyacrylamide gel beads were prepared via inverse-phase suspension polymerization,
using acrylamide and N,N′-methylene diacrylamide as polymeric matrix components and methacrylic acid as functional monomer. The adsorption study showed,
through the imprinting process, that the imprinted gel beads had much higher adsorption capacity than the nonimprinted gel
beads, and that the matching of the surface zeta-potential between the templates and the imprinted gel beads can enhance the
imprinting effect. Adsorption kinetics indicated that the adsorption process could be described as an apparent first-order
kinetic process for the gel beads. From the adsorption isotherm curve, we found that the adsorption of the imprinted gel beads
was in agreement with the Langmuir adsorption model. Moreover, selectivity testing of the imprinted gel beads showed that
imprinted gel beads exhibited good recognition for BSA as compared to the control protein. We speculate that the formation
of complementary shapes and multiple-point electrostatic interactions between the imprinting cavities and the template proteins
are the two factors that lead to the imprinting effect.
相似文献
12.
Human serum albumin magnetic microspheres containing 30% iron oxide particles were synthesized by a heat-stabilization process.
The average diameter, the size distribution and the morphology were characterized by scanning electron microscopy, atomic
force microscopy and transmission electron microscopy. The distribution of the iron oxide nanoparticles within the microspheres
was confirmed by the contrast obtained in the morphology by backscattered electron imaging in scanning electron microscopy.
Energy-dispersive X-ray spectroscopy showed the presence of iron in the microspheres. The cabbage like surface structure in
some of the microspheres obtained in scanning electron microscopy can be better understood by atomic force microscopy. This
peculiar surface structure in the microsphere may be due to the cross-linking in the protein molecule by heat. The amount
of iron oxide in the microsphere was analyzed by atomic absorption spectroscopy. The magnetic properties of the particles
were measured in a superconducting quantum interference device magnetometer.
Received: 12 September 2000 Accepted: 5 February 2001 相似文献
13.
In this study, acrylamide–itaconic acid hydrogels containing different amounts of itaconic acid prepared by irradiating with γ radiation are discussed. They have been used in experiments of swelling, diffusion and bovine serum albumin (BSA) adsorption. Maximum and minimum swellings were observed with water (1520%) and BSA (890%), respectively. Diffusion of water, NaCl and BSA within hydrogels were found to be non-Fickian in character. In the experiments of BSA adsorption, type III adsorption was found. The hydrogel prepared with 60 mg itaconic acid and irradiated at 2.00 kGy was found to be the best adsorption system for BSA. The adsorption capacity of acrylamide–itaconic acid hydrogel was found to exceed that of acrylamide hydrogel by more than 80–100%. 相似文献
14.
The interactions between oleanolic acid and bovine serum albumin (BSA) have been studied by fluorescence, circular dichroism (CD), UV–vis absorption and Fourier transform infrared spectroscopy (FTIR) under physiological conditions. Spectroscopic analysis of the emission quenching at different temperatures has revealed that the quenching mechanism of bovine serum albumin by oleanolic acid is static quenching mechanism. The binding sites number n and binding constants K are obtained at various temperatures. The distance r between oleanolic acid and the protein is evaluated according to the theory of Forster energy transfer. The results by FTIR, CD and UV–vis absorption spectra experiment indicate that the secondary structures of protein have been perturbed in the presence of oleanolic acid. The thermodynamic parameters ΔH0, ΔG0, and ΔS0 are calculated according to van’t Hoff equation, which indicates that the hydrogen bonds and van der-waals are the intermolecular forces stabilizing the complex. Molecular modeling studies the interaction BSA with oleanolic acid. 相似文献
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Lida Fotouhi Sara Banafsheh Majid M. Heravi 《Bioelectrochemistry (Amsterdam, Netherlands)》2009,77(1):26-30
The electrochemical behavior of the interaction of furazolidone (Fu) with bovine serum albumin (BSA) was investigated by cyclic voltammetry and differential pulse voltammetry at a glassy carbon electrode. Fu shows an irreversible reduction at − 0.34 V in pH 4.0 Britton–Robinson buffer (B–R) buffer–10% DMF solution. After the addition of BSA into the Fu solution, the reductive peak currents decreased without any significant shift of the peak potential and the appearance of new peaks. The electrochemical parameters of the interaction system were calculated in the absence and presence of BSA. This electrochemical method was further applied to the determination of BSA samples and the results were in good agreement with the traditional cellulose acetate electrophoresis. The linear dynamic range was between 10.0 and 80.0 mg l− 1. The detection limit was 7.6 mg l− 1 and the recoveries were obtained from 97.0% to 104.0%. 相似文献
17.
金丝桃苷与牛血清白蛋白相互作用的研究 总被引:1,自引:0,他引:1
采用荧光共振能量转移法研究了金丝桃苷与牛血清白蛋白的相互作用.金丝桃苷对牛血清白蛋白(BSA)的荧光猝灭类型是静态猝灭,25℃时的结合位点数为0.5451.并依据F(o)ster非辐射能量转移理论,研究了给体(牛血清白蛋白)--受体(金丝桃苷)间的结合距离R.和能量转移效率E分别为2.04nm和0.66.同时,采用同步... 相似文献
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以电化学方法对秋水仙碱与牛血清白蛋白的相互作用进行了研究。在0.3 mol/L H2SO4底液中,秋水仙碱在玻碳电极上产生一不可逆的氧化峰,峰电位为1.18 V(vs.SCE),加入表面活性剂四丁基氯化铵后,秋水仙碱的峰信号得到明显提高。在上述条件下,加入BSA后秋水仙碱的氧化峰电位正移,峰电流下降,峰电流下降值与BSA加入的浓度在1.5×10-7~2×10-6mol/L(r=0.9978)范围内有良好的线性关系,检出限达4.0×10-8mol/L。进一步探讨了秋水仙碱与BSA的结合数和结合常数,得到结合数为1,结合常数为2.40×105L/mol。 相似文献
20.
Hui Lin Jingfeng Lan Min Guan Fenling Sheng Haixia Zhang 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,73(5):936-941
The mechanism of interaction between mangiferin (MA) and bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence spectra, synchronous fluorescence spectra, absorbance spectra and Fourier transform infrared (FT-IR) spectroscopy. The binding constants and binding sites of MA to BSA at different reaction times were calculated. And the distance between MA and BSA was estimated to be 5.20 nm based on Föster's theory. In addition, synchronous fluorescence and FT-IR measurements revealed that the secondary structures of the protein changed after the interaction of MA with BSA. As a conclusion, the interaction between the anti-diabetes Chinese medicine MA and BSA may provide some significant information for the mechanism of the traditional chinese medicine MA on the protein level to cure diabetes or other diseases. 相似文献