溴代苯酚与牛血清白蛋白的相互作用研究

Study on the Binding Interactions between Bromophenols and Bovine Serum Albumin

消毒副产物(Disinfection By-products,DBPs)是水环境中一类重要的污染物,因其检出频率高于对人的健康风险而引起广泛关注。牛血清白蛋白(BSA)作为水溶性最大的蛋白,可通过与水中DBPs发生结合作用而影响其环境行为。选取溴代芳香族DBPs 4-溴苯酚(4BPh)和2,4-二溴苯酚(24DBPh),运用荧光光谱法、紫外-可见光谱法和分子对接法,研究了其与BSA的相互作用机制。结果显示,两种溴代DBPs均能与BSA结合而猝灭BSA的内源荧光,并使BSA构象发生改变,且溴化程度越高结合作用越强;290 K条件下,4BPh和24DBPh对BSA的结合常数分别为5.391×10^(2)、2.644×10^(4) L/mol。分子对接结果显示4BPh和24DBPh与BSA的结合位点均在结构域ⅢA中,氢键是结合的主要作用力。研究结果有助于深入探明水环境中大分子如BSA对DBPs环境行为的影响机制。

Disinfection byproducts(DBPs)in water environments received great attention due to the frequent detection of various water matrix and potential health risks to human beings.Interactions between bovine serum albumins(BSA),the most abundant water-soluble protein,and DBPs possibly occur,which as a result influence the environmental behaviors of DBPs.The binding interactions of 4-bromophenol(4BPh)and 2,4-dibromophenol(24DBPh)with BSA were investigated systematically in this study by using fluorescence spectrometry,UV spectrometry and molecular docking.The results indicated that both 4BPh and 24DBPh could quench the intrinsic fluorescence of BSA through binding interactions,accompanied with the conformation changes of BSA.The binding effects increased with the degree of bromination.24DBPh(K b=2.644×10^(4) L/mol)showed higher binding affinity than 4BPh(K b=5.391×10^(2) L/mol),which determined by the binding constants(K b)at T=290 K.The docking analysis suggested that hydrogen bonding was the primary interaction forces and both of 4BPh and 24DBPh were located in the subdomainⅢA of BSA.The results of the present study were helpful in further understanding of influence mechanisms of macromolecules such as BSA on the environmental behaviors of DBPs in water environments.