磺胺二甲异恶唑与HSA的结合性质及其对HSA结构的影响

发布时间：2018-05-12 14:46

本文选题：磺胺二甲异恶唑 + 人血清白蛋白　；参考：《南昌大学学报(理科版)》2015年04期

【摘要】：在模拟人体生理酸度条件下(pH 7.4),运用荧光、紫外、红外和圆二色光谱法结合分子模拟技术,研究了磺胺二甲异恶唑(SIZ)与人血清白蛋白(HSA)的相互作用。荧光猝灭实验表明,SIZ对HSA的荧光猝灭属于形成复合物的单一静态猝灭。SIZ与HSA有中等强度的亲合力,结合常数在104 L·mol-1数量级,结合位点数近似等于1,计算热力学参数焓变(ΔHΘ=-25.24kJ·mol-1)和熵变(ΔSΘ=-4.53J·mol-1·K-1)值表明,氢键与范德华力是SIZ与HSA相互作用的主要驱动力。荧光竞争实验表明,SIZ位于HSA亚结构域IIA的疏水空腔(Site I位),分子模拟证实了这一结果。紫外、同步荧光、圆二色谱和红外光谱分析以及蛋白质表面疏水性测定显示,SIZ与HSA结合诱导了HSA的二级结构发生了部分改变,蛋白质多肽链部分伸展,结构松散,使α-螺旋含量降低,HSA表面疏水性降低。
[Abstract]:The interaction between sulfamethoxazolium (SIZ) and human serum albumin (HSA) was studied by fluorescence, UV, IR and circular dichroism spectroscopy combined with molecular simulation technique under simulated physiological acidity of human body. Fluorescence quenching experiments show that the fluorescence quenching of HSA by Sizz belongs to the single static quenching of the complex. SIZ has a moderate affinity to HSA, and the binding constant is in the order of 104L mol-1. The calculated thermodynamic parameter enthalpy change (螖 H -25.24 kJ mol -1) and entropy change (螖 S -4.53J mol-1 K-1) indicate that hydrogen bond and van der Waals force are the main driving forces for the interaction between SIZ and HSA. Fluorescence competition experiments show that the siz is located in the hydrophobic cavity site I of the HSA subdomain IIA, which is confirmed by molecular simulation. UV, synchronous fluorescence, circular dichroism, infrared spectroscopy and surface hydrophobicity analysis showed that Sizz combined with HSA induced partial changes in the secondary structure of HSA, the protein polypeptide chain was partially extended and the structure was loose. The hydrophobicity of HSA surface was decreased by reducing 伪 -helix content.
【作者单位】：南昌大学食品科学与技术国家重点实验室;南昌大学期刊社;
【基金】：国家自然科学基金项目(21167013,31460422) 江西省自然科学基金项目(20143ACB20006,20142BAB204001) 江西省科技支撑项目(20141BBG70092)
【分类号】：R914;O657.3

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