复合纳米颗粒中白藜芦醇-大麦醇溶蛋白相互作用研究

Study on the Interaction in Resveratrol-Hordein Nanoparticle

为阐明大麦醇溶蛋白包覆白藜芦醇形成纳米颗粒的分子机制,采用荧光光谱、紫外吸收光谱以及傅里叶红外光谱和差示扫描量热技术等研究了白藜芦醇与大麦醇溶蛋白分子间的相互作用。结果表明:白藜芦醇与大麦醇溶蛋白分子的相互作用,对其内源性荧光具有猝灭作用,结合差示扫描量热的结果,推测二者通过静态猝灭过程形成了新的复合物;计算出两者之间的结合常数与结合位点数分别为K_(A(298K))=2.21×10~5 L·mol^(-1),K_(A(310K))=1.53×10~4 L·mol^(-1)和n_(298K)=1.23,n_(310K)=0.94;依据热力学参数和傅里叶红外光谱判断白藜芦醇与大麦醇溶蛋白之间的作用力为范德华力和氢键相互作用;根据Frster非辐射能量转移原理,计算出白藜芦醇与大麦醇溶蛋白的结合距离为3.25nm,能量转移效率为0.227;同步荧光检测结果表明白藜芦醇结合大麦醇溶蛋白分子后对其构象产生了明显影响,且该影响是由色氨酸残基所处环境的疏水性变化所致。

In order to clarify the interaction mechanism of the formation of the resveratrol-hordein nanoparticle,the fluorescence,UV-Vis spectroscopic,FTIR and DSCwere used to study the binding reaction between resveratrol and hordein.The fluorescent emission of hordein was inhibited by resveratrol in a dose dependent manner.Fluorescence spectroscopy and DSC indicated that resveratrol interacted with hordein and formed a new complex by a static process.The binding constant（K_（A（298K））=2.21×10^5L·mol^-1,K_（A（310K））=1.53×10^4 L·mol^-1）and the number of binding sites（n_（298K） =1.23,n_（310 K ）=0.94）were calculated based on the quenching effect of resveratrol on hordein.Thermodynamic parameter and FTIR indicated that the interaction force between resveratrol and hordein was mainly hydrogen binding and van der Waals force.The binding distance（r0=3.25nm）between resveratrol and hordein and the energy transfer efficiency（E=0.227）were obtained according to non-radiative energytransfer theory.The effect of resveratrol on the conformation of hordein was further analyzed by using synchronous fluorescence spectrometry.The results indicated that resveratrol changed the hydrophobicity of tryptophan residue,which caused an obvious influence on the conformation of hordein.