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吡虫啉与牛血红蛋白相互作用的光谱研究 总被引:2,自引:0,他引:2
利用紫外可见光谱和荧光光谱研究了在生理pH值条件下农药吡虫啉与牛血红蛋白(BHb)的相互作用。实验结果表明:吡虫啉分子与BHb发生反应生成复合物,导致BHb内源荧光的猝灭,该猝灭属于静态猝灭。测定了不同温度下该反应的表观结合常数、结合位点数及结合热力学参数,热力学参数的变化表明上述作用过程是一个熵增加、自由能降低的自发分子间作用过程,吡虫啉与BHb之间以静电和疏水作用力为主;并用同步荧光光谱法探讨了吡虫啉对BHb构象的影响。 相似文献
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硅钨杂多酸与牛血红蛋白相互作用的研究 总被引:4,自引:0,他引:4
多金属氧酸盐作为抗艾滋病病毒、抗流感病毒和抗肿瘤的药物,引起了人们对多金属氧酸与蛋白质之间相互作用的极大关注。蛋白质空间结构的任何变化引起的构象变化都意味着蛋白质分子的活性改变,因此,蛋白质与内源性化合物及许多药物分子之间相互作用的研究一直受到人们关注[1 ̄3]。血红蛋白是动物及人体内执行输氧任务的蛋白质,是生命机体进行各种生理活动的主要承担者。血红蛋白分子中每条α链和β链含有的色氨酸(Trp)残基分别为α-14Trp、β-15Trp、β-37Trp。Alpert[4]等认为位于疏水腔内的β-37Trp是血红蛋白内源荧光的主要来源,同时β… 相似文献
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单宁酸与牛血红蛋白相互作用的光谱研究 总被引:1,自引:1,他引:1
利用荧光光谱技术研究了单宁酸与牛血红蛋白分子的相互作用。实验结果表明:单宁酸分子与BHb发生反应生成基态复合物,导致BHb内源荧光的猝灭,该猝灭属于静态猝灭。测定了不同温度下该反应的表观结合常数、结合位点数及结合热力学参数,热力学参数的变化表明上述作用过程是一个熵增加、自由能降低的自发分子间作用过程,单宁酸与BHb之间以疏水和氢键作用力为主;根据Frster能量转移理论,测得供体与受体间结合距离r和能量转移效率E;并用同步荧光光谱法探讨了单宁酸对BHb构象的影响。 相似文献
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运用荧光光谱、紫外-可见吸收光谱和圆二色谱法研究了双十二烷基二甲基溴化铵(DDAB)与牛血红蛋白(Hb)的相互作用。从紫外-可见吸收光谱观察到,随着DDAB的浓度增大,Hb在406nm处的特征吸收峰强度下降,且峰位蓝移,说明DDAB导致血红素辅基微观环境变化。由荧光光谱研究可以得出随着DDAB的浓度增大,Hb在340nm处的荧光强度逐渐增强,说明导致色氨酸荧光淬灭的血红素辅基与色氨酸的距离增大。由Scatchard方程计算了不同温度下该反应的表观结合常数、结合位点数及结合热力学参数,热力学参数的变化表明DDAB与Hb之间以疏水作用力为主。圆二色谱的研究进一步表明DDAB使Hb产生轻微的二级结构改变,α-螺旋含量增加. 相似文献
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光谱法研究铬(Ⅵ)与血红蛋白的相互作用 总被引:2,自引:0,他引:2
运用荧光光谱、紫外光谱、CD光谱法研究了K2Cr2O7与牛血红蛋白(BHb)的相互作用。紫外光谱表明,加入铬(Ⅵ)酸根离子后,BHb分子中Soret带的吸收持续降低, 峰位红移,说明铬(Ⅵ)酸根离子可能使部分血红素辅基从BHb的空腔中脱离出来,部分转变为高铁血红蛋白。荧光光谱表明,铬(Ⅵ)酸根离子与BHb形成基态复合物导致BHb内源荧光猝灭,猝灭机理主要为静态猝灭。测定了不同温度下该反应的热力学参数,表明上述作用过程是一个熵增加、自由能降低的自发分子间作用过程,铬(Ⅵ)酸根离子与BHb之间以氢键和范徳华力相互作用为主;并用同步荧光和CD光谱技术考察了铬(Ⅵ)对BHb结构的影响。 相似文献
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本文采用紫外光谱(UV/VIS)、荧光光谱和圆二色谱等方法,对汞(Ⅱ)与牛血红蛋白(BHb)的相互作用进行了研究.结果表明:Hg2 处理导致BHb紫外吸收的增加,出现LMCT带,并随Hg2 浓度的增加LMCT带强度显著增强.BHb分子中Soret带的吸收随着Hg2 作用时间的增加而持续降低,表明Hg2 使部分血红素辅基从BHb中脱离出来.蛋白内源荧光光谱显示,Hg2 与BHb的结合会影响蛋白质的三级结构和四级结构.远紫外圆二色谱表明,Hg2 处理会导致BHb蛋白的α-螺旋含量减少. 相似文献
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本文采用紫外光谱(UV/VIS)、荧光光谱和圆二色谱等方法,对汞(II)与牛血红蛋白(BHb)的相互作用进行了研究。结果表明:Hg2 处理导致BHb紫外吸收的增加,出现LMCT带,并随Hg2 浓度的增加LMCT带强度显著增强。BHb分子中Soret带的吸收随着Hg2 作用时间的增加而持续降低,表明Hg2 使部分血红素辅基从BHb中脱离出来。蛋白内源荧光光谱显示,Hg2 与BHb的结合会影响蛋白质的三级结构和四级结构。远紫外圆二色谱表明,Hg2 处理会导致BHb蛋白的α-螺旋含量减少。 相似文献
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Edwin W. Y. Wong Akito Miura Mathew D. Wright Qi He Prof. Charles J. Walsby Dr. Soji Shimizu Prof. Nagao Kobayashi Prof. Daniel B. Leznoff 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12404-12410
In 1965, gold(II) phthalocyanine (AuPc, 1 ) was described to be synthesized from unsubstituted 1,3‐diiminoisoindoline and gold powder or AuBr. Compound 1 has been regarded as a rare example of a paramagnetic gold(II) complex. However, its chemistry, especially the oxidation state of the central gold ion, has not been previously explored due to the inherent insolubility of 1 caused by its unsubstituted structure. In our attempt to synthesize soluble AuPcs by using 5,6‐di‐substituted 1,3‐diiminoisoindolines, gold(III) phthalocyanine chloride ( 3 ) and a gold(III) complex of an unprecedented ring‐contracted phthalocyanine analogue ([18]tribenzo‐pentaaza‐triphyrin(4,1,1), 4 ) were isolated. With this discrepant result from the original literature in hand, a reinvestigation of the original AuPc synthesis by using unsubstituted 1,3‐diiminoisoindoline and various gold salts (including gold powder and AuBr) was performed, finding that only unsubstituted analogues of 3 and 4 or free‐base phthalocyanine were obtained. No gold(II)‐containing species could be isolated. 相似文献
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The interaction between bovine hemoglobin (BHb) and TiO(2) colloid was investigated by UV/vis absorption, UV/vis diffuse reflectance spectrum, IR, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques under physiological pH 7.40. TiO(2) effectively quenched the intrinsic fluorescence of BHb via static quenching. The process of binding TiO(2) on BHb was a spontaneous molecular interaction procedure. The thermodynamic parameters, DeltaH degrees and DeltaS degrees were estimated to be -78.07 kJ mol(-1), -110.93 J mol(-1)K(-1) according to the van' Hoff equation. This indicates that the van der Waals and hydrogen bonds interactions played a major role in stabilizing the TiO(2)-BHb complex. The effect of TiO(2) on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy. 相似文献
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Maryam Saeidifar Hassan Mansouri‐Torshizi Adeleh Divsalar Ali.Akbar Saboury 《中国化学会会志》2013,60(2):133-139
The interaction of human serum albumin (HSA) with 1,10‐phenanthroline‐ethyldithiocarbamatopalladium(II) nitrate complex, [Pd(phen)(Et‐dtc)]NO3, has been studied by using absorption, fluorescence and circular dichroism spectroscopic measurements. UV‐Vis studies imply that The peptide strands of protein molecules extended more (denatured) upon the addition of Pd(II) complex. This process is spontaneous and exothermic. A fluorescence quenching reaction of Pd(II) complex and HSA was observed and quenching mechanism was suggested as static quenching according to Stern‐Volmer equation. The number of binding sites (n) and apparent association constant (KA) were calculated using fluorescence quenching data. The circular dichroism results revealed the conformational changes in secondary structure of protein upon its interaction with Pd(II) complex. In these interaction studies, several thermodynamic and binding parameters are also determined which may provide deeper insights into structural changes induced by an antitumor Pd(II) complex on the protein as the metal complex side effects. 相似文献
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采用多种光谱技术对喜树碱和牛血清白蛋白的相互作用进行了研究.结果表明喜树碱和牛血清白蛋白可形成基态复合物,引起牛血清白蛋白内源荧光猝灭.通过计算获得了二者在不同温度下的结合常数及结合位点数.根据喜树碱和牛血清白蛋白结合的热力学参数,确定了二者之间主要为疏水作用力.根据F(o)rster非辐射能量转移理论确定了喜树碱和牛血清白蛋白的作用距离.同步荧光光谱显示喜树碱主要与蛋白中色氨酸残基发生相互作用,改变其周围的局部构象.红外光谱提示喜树碱可引起蛋白的构象发生改变,α-螺旋二级结构减少. 相似文献