1-萘酚诱导人血清白蛋白和牛血清白蛋白构象的变化  

Conformational Changes of Human Serum Albumin and Bovine Serum Albumin Induced by 1-Naphthol

作　　者：李梦硕 朱亚先[2] 张勇 LI Meng-shuo;ZHU Ya-xian;ZHANG Yong(State Key Laboratory of Marine Environmental Sciences of China,College of Environment and Ecology,Xiamen University,Xiamen 361102,China;Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University, Xiamen 361005,China)

机构地区：[1]近海海洋环境科学国家重点实验室,厦门大学环境与生态学院,福建厦门361102 [2]厦门大学化学化工学院化学系,福建厦门361005

出　　处：《分析测试学报》2021年第6期914-919,共6页Journal of Instrumental Analysis

基　　金：国家自然科学基金委重大科研仪器研制项目(21627814)。

摘　　要：采用稳态荧光光谱、同步荧光光谱、荧光共振能量转移技术结合分子对接法,探究了1-萘酚(1-OHNap)诱导人血清白蛋白(HSA)和牛血清白蛋白(BSA)构象变化的差异。结果表明,与1-OHNap的结合作用使HSA中荧光团周围微环境极性发生改变,BSA中Trp残基周围微环境的极性增加;同时,与1-OHNap的结合作用使HSA、BSA中的多肽链轻微展开,其中HSA中α-螺旋占比的降幅较大;1-OHNap与HSA、BSA的结合平衡常数(Kb)分别为1.49×10^(4)、8.76×10^(3) L/mol;1-OHNap分别结合在HSA和BSA的ⅡA子域和ⅠB子域;1-OHNap与HSA和BSA中Trp残基的表观距离分别为1.53 nm和1.42 nm。实验证实1-OHNap诱导HSA和BSA构象的变化具有差异。The typical polycyclic aromatic hydrocarbons(PAHs)metabolite 1-napthol(1-OHNap)is ubiquitously existing in smoker's blood.It's worth paying attention to the binding interaction between the most abundant transport albumin and 1-OHNap at molecular level.The crystal structures of human serum albumin(HSA)and bovine serum albumin(BSA)are different.There are still many studies using BSA as model protein to investigate the ligand-protein interactions.The main aim here was to explore the differences of binding mechanism between carrier protein HSA and BSA with 1-OHNap under the simulated physiological condition.The binding interactions between 1-OHNap and two serum albumin were investigated by steady-state fluorescence spectra,synchronous fluorescence spectra,CD spectra,fluorescence resonance energy transfer technique and molecular docking method.The fluorescence quenching experimental results showed that 1-OHNap interacted with both tryptophan(Trp)and tyrosine(Tyr)residues in HSA and BSA.The position and strength of characteristic fluorescence spectra of both HSA and BSA had been changed differently after binding with 1-OHNap.Meanwhile,the synchronous fluorescence spectra experimental results suggested that the binding interactions with 1-OHNap changed the polarity of the microenvironment of binding sites around the fluorophore in HSA.Besides,the binding interaction with 1-OHNap increased the polarity of the microenvironment around Trp residues in BSA.Then,the CD spectra were used to obtain the changes in the secondary structure of HSA and BSA after binding with 1-OHNap.The CD spectra experimental results indicated that the binding interaction with 1-OHNap caused the slight unfolding of polypeptide chains in both HSA and BSA.The amplitudes of theα-helical ratios of both HSA and BSA decreased after binding with 1-OHNap.Furthermore,the decreasing amplitude of theα-helical ratio of BSA was lower than that of HSA.The binding constants of 1-OHNap with HSA and BSA were calculated by using double logarithmic equation fitting

关 键 词：1-萘酚 荧光猝灭 构象变化 人血清白蛋白 牛血清白蛋白 

分 类 号：O657.3[理学—分析化学]