共查询到20条相似文献,搜索用时 15 毫秒
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I. M. Vlasova V. V. Zhuravleva A. M. Saletskii 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(6):1027-1034
The tryptophan fluorescence of bovine serum albumin (BSA) in solutions with different concentrations of cationic detergent cetyltrimethylammonium bromide (CTAB) at different pH is investigated, providing information on BSA denaturation under the action of CTAB. It is found that BSA denaturation under the action of CTAB at all of the investigated pH values (3.5–8.0) is a single-stage process, as determined by BSA tryptophan fluorescence quenching, by an increased degree of the BSA tryptophan fluorescence polarization, and by the values of the parameters for the rotational diffusion of BSA molecules in CTAB solutions. It is shown that the cationic detergent CTAB is more efficient for BSA denaturation at pH values higher than the BSA isoelectric point (4.9). 相似文献
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This work deals with the application of BSA and canine serum albumin (CSA) for enantioseparation of tryptophan derivatives with CE. The aim of this work was the investigation of the influence of different functional groups of tryptophan derivatives on enantioseparation. CSA as a chiral selector was tested to compare its selector properties with those of BSA. The enantiomers of the tryptophan derivatives were separated by adding BSA or CSA to the BGE. The influence of pH, temperature, BSA and CSA concentration and organic modifiers was investigated. It was found that the stereoselectivity for the different tryptophan derivatives is dependent on the albumin species. It turned out that the different functional groups of the derivatives showed a significant influence on stereoselectivity. 相似文献
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荧光光谱法研究4-硝基苯胺与牛血清白蛋白的相互作用 总被引:1,自引:0,他引:1
在模拟动物生理条件下利用荧光光谱法从分子水平上研究了4-硝基苯胺同牛血清白蛋白(BSA)的相互作用.4-硝基苯胺对BSA的荧光有较强猝灭作用.用Stern-Volmer方程和双对数方程分别处理实验数据发现BSA与4-硝基苯胺发生反应生成了新的复合物,猝灭机理以静态碎灭为主.根据双对数方程求出了不同温度下反应时复合物的形... 相似文献
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Two classes of binding sites, a single high-affinity site with an association constant of 4·8×106 M−1 and two low-affinity sites with association constant of about 0·05×106 M−1 have been observed in the interaction of Naproxen with bovine serum albumin (BSA). Chemical modification of two tryptophan
residues in BSA with 2-hydroxy-5-nitrobenzyl bromide has led to a reduction in the association constant of the high-affinity
site by 89% and its number of binding sites by 66% suggesting the involvement of tryptophan residues in the high-affinity
site. In contrast, the two low-affinity sites were not affected by the modification. Binding of Naproxen to the low-affinity
sites of BSA induces microdisorganisation of the albumin structure leading to conformational changes as evident from fluorescence
measurements with 1-anilino-8-naphthalenesulphonic acid as the probe. 相似文献
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应用荧光光谱技术,对尿素与牛血清蛋白在30℃水溶液中的结合作用及造成牛血清蛋白变性的过程进行了研究,获取了尿素诱导牛血清蛋白变性时相对荧光强度和峰位的变化规律.用Pace等提出的公式分析了相对荧光强度数据,得到了牛血清蛋白变性时的伸展分数fu随溶液pH值和尿素浓度的变化规律.求出了变性平衡常数Ku,伸展吉布斯自由能△G... 相似文献
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I. M. Vlasova E. M. Bukharova A. M. Saletskii 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(5):876-880
Rotational diffusion of fluorescein family nanomarkers (initial fluorescein and its halogenated derivatives, eosin and erythrosine)
in solutions of human serum albumin (HSA) was studied at various pH values. In solutions of HSA, the degree of fluorescence
polarization, rotational relaxation time, and Einstein radius of nanomarkers are larger and the rotational diffusion coefficient
of nanomarkers smaller than in solutions without the protein. An increase in the electronegativity of atoms in the structural
formulas of nanomarkers increases the degree of polarization of their fluorescence, decreases the coefficient of their rotational
diffusion, and increases rotational relaxation time and the effective Einstein radius. 相似文献
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Yan-Jun Hu Yi Liu Li-Xia Zhang Ru-Ming Zhao Song-Sheng Qu 《Journal of Molecular Structure》2005,750(1-3):174-178
We investigated the interaction between colchicine and bovine serum albumin (BSA) by fluorescence and UV–Vis absorption spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by colchicine is a result of the formation of colchicine–BSA complex; van der Waals interactions and hydrogen bonds play a major role in stabilizing the complex. The modified Stern–Volmer quenching constant Ka and corresponding thermodynamic parameters ΔH, ΔG, ΔS at different temperatures were calculated. The distance r between donor (BSA) and acceptor (colchicine) was obtained according to fluorescence resonance energy transfer (FRET). 相似文献
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Modified Stern-Volmer equation is obeyed by bovine serum albumin (BSA)-iodide system showing selective quenching of tryptophanyl
fluorescence of BSA. The fraction of accessible protein fluorescence is 0.56 and the effective Stern-Volmer constant is 290
M-1 at pH 7.4 in 0.005 M phosphate buffer at 25°C. Collisional quenching is operative both in the BSA -I−1 system and the model system, tryptophan-I−1. It is supported by the observed relationship between the ratio of quenching rate constants (k
q
) and diffusion coefficients and alsok
q
with bulk viscosity. 相似文献
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Daphnetin (7,8-dihydroxycoumarin), one of the major bioactive components isolated from Daphne koreane Nakai, has been used in traditional Chinese medicine for the treatment of coagulation disorders. It is also a chelator, an antioxidant and a protein kinase inhibitor. In this paper, a combination of intrinsic fluorescence, Fourier transform infrared (FT-IR) spectroscopy and circular dichroic (CD) spectroscopy has been used to characterize the binding between daphnetin and human serum albumin (HSA) under physiological conditions with drug concentrations of 6.7 x 10(-6) - 2.3 x 10(-5) mol x L(-1), and a HSA concentration of 1.5 x 10(-6) mol x L(-1). Changes in the CD spectra and FT-IR spectra were observed upon ligand binding, and the degree of tryptophan fluorescence quenching did change significantly in the complexes. These data have proved the change in protein secondary structure accompanying ligand binding. The change in tryptophan fluorescence intensity was used to determine the binding constants. The thermodynamic parameters, the enthalpy change (DeltaH) and the entropy change (DeltaS) were calculated to be -12.45 kJ x mol(-1)and 52.48 J x mol(-1) x K(-1) according to the van't Hoff equation, which indicated that hydrophobic and electrostatic interactions played the main role in the binding of daphnetin to HSA, in accordance with the results of calculations performed on a Silicon Graphics Ocatane2 workstation. In addition, the binding distance between daphnetin and HSA was obtained (4.02 nm) based on the Forster energy transfer theory. 相似文献
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在模拟生理条件下(pH=7.40),应用荧光光谱、吸收光谱和同步荧光光谱法探讨了不同温度下尼泊金乙酯钠(Ethylparaben Sodium,EPS)与牛血清白蛋白(Bovine Serum Albumin,BSA)相互作用的机制.荧光光谱和吸收光谱分别表明:尼泊金乙酯钠对BSA内源荧光有明显猝灭作用,属于静态猝灭,二者的猝灭作用是由于尼泊金乙酯钠与BSA形成基态复合物导致的.运用双对数方程求得291、310 K时的结合常数分别为3.23×106、3.63×105L·mol-1,结合位点数分别为0.99和0.84.运用热力学方程得出热力学参数(ΔH,ΔS),通过ΔH0,ΔS0可知二者之间的作用力主要是氢键或范德华力.同步荧光光谱表明尼泊金乙酯钠对BSA结构的构象会产生影响.本研究为EPS的毒理和生物学效应提供了重要的参考信息. 相似文献
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Investigation of the association behaviors between biliverdin and bovine serum albumin by fluorescence spectroscopy 总被引:2,自引:0,他引:2
The interaction between biliverdin and bovine serum albumin (BSA) has been studied by steady fluorescence spectroscopy, synchronous fluorescence and resonance light scanning spectra. The binding of biliverdin to BSA quenches the tryptophan residue fluorescence and the results show that both static and dynamic quenching occur together with complex formation. The binding constant and binding sites of biliverdin to BSA at pH 7.1 are calculated to be 3.33 × 108 L/mol and 1.54, respectively, according to the double logarithm regression curve. In addition, the distance between the biliverdin and BSA is estimated to be 1.25 nm using Föster's equation on the basis of the fluorescence energy transfer. Furthermore the synchronous fluorescence spectra show that the microenvironment of the tryptophan residues has not obvious changes, which obeys the phase distribution model. Finally, the thermodynamic data show that biliverdin molecules enter the hydrophobic cavity of BSA via hydrophobic interaction. 相似文献