4-羟基-二苯甲酮与牛血清白蛋白相互作用的研究:多光谱分析和分子对接

Study of the interaction between 4-hydroxybenzophenone and bovine serum albumin:multispectral analysis and molecular docking

4-羟基-二苯甲酮(4-HBP)是一种常见的二苯甲酮类紫外线吸收剂,但也是一种环境污染物.本文采用荧光光谱法、紫外光谱法和红外光谱法等表征方法,结合分子对接技术研究了4-HBP与牛血清白蛋白(BSA)的结合机制.298 K时,4-HBP与BSA的结合常数(Kb=3.46×10^(5)L·mol^(-1))和结合位点数(n=1.17)表明,二者会以较高的结合亲和力,形成相对稳定的1∶1复合物.4-HBP通过范德华力自发结合在BSA的位点Ⅱ.紫外光谱法、三维荧光光谱法和红外光谱法分析结果表明,4-HBP使BSA氨基酸周围微环境的极性减小,疏水性增加;BSA二级结构中α-螺旋和反平行β-折叠含量减少,β-折叠、无规则卷曲和β-转角的含量增加.

Up to date,anti-ultraviolet agent,an important kind of pharmaceutical and personal care products,has been widely applied in daily life.4-hydroxybenzo-phenone(4-HBP)is a common of benzophenone-type UV filters,but it is also an environmental pollutant detected in water bodies,sediments,and aquatic.And 4-HBP poses negative influences,such as genetic toxicity and endocrine interference on the human body and organism.What is worse,4-HBP has a long residual period in the environment due to its low biodegradability.Serum albumin(SA)is the most abundant protein in mammalian blood plasma.It can bind with many intrinsic and extrinsic materials.In particular,SA plays an important role in the absorption,depot,distribution,transport,metabolism,excretion,and toxicity of small molecules in vivo.Furthermore,these contaminants bind in the active sites of the protein resulting in structural and functional changes and may also cause toxic effects.Bovine serum albumin(BSA)is one of the most extensively utilized protein in laboratory practice and is used as a human serum albumin(HSA)substitute in many experiments due to its structural homology with HSA.The binding mechanism of 4-HBP to bovine serum albumin(BSA)was studied by fluorescence spectroscopy,ultraviolet spectroscopy and infrared spectroscopy,and molecular docking technology.At 298 K,the binding constant(K_b=3.46×10^(5)L·mol^(-1))and the number of binding sites(n=1.17)of 4-HBP to BSA indicated that 4-HBP could form a relatively stable 1∶1 complex with high binding affinity.And 4-HBP spontaneously binds to siteⅡof BSA through van der Waals force.The results of ultraviolet spectroscopy,three-dimensional fluorescence spectroscopy and infrared spectroscopy showed that 4-HBP decreased the polarity and increased the hydrophobicity of the microenvironment around BSA amino acids.The contents ofα-helix and anti parallelβ-sheet in BSA secondary structure decreased,while the contents ofβ-sheet,random coil andβ-turn increased.