FTIR-ATR study for adsorption of trypsin in aqueous environment on bare and TiO2 coated ZnSe surfaces  

作　　者：Chune Guo Xiaomi Guo Wubo Chu Nan Jiang He Li 

机构地区：[1]Key Laboratory of Marine Materials and Related Technologies,CAS,Zhejiang Key Laboratory of Marine Materials and Protective Technologies,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China [2]College of Materials Science and Optoelectronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Chemical Letters》2020年第1期150-154,共5页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.21675165)

摘　　要：Undesired adsorption of proteins brings big troubles to marine structures.The settled proteins change the physical and chemical properties of the surfaces,which allow marine fouling organisms to settle down on the structures.Therefore,to understand the adsorption mechanism of proteins is very helpful to find an environment-friendly solution against biofouling.Many approaches have been developed to study protein adsorption,but most of them are insufficient to give the chemical interaction information between proteins and surfaces.Fourier transform infrared spectroscopy with attenuated total reflection(FTIR-ATR)is an efficient,fast and non-destructive method for in situ surface measurement,which greatly minimizes the interference of water to infra red spectra,because of the very small depth of penetration of the evanescent wave.In this paper,an in situ FTIR-ATR technology was used to investigate the adsorption process of trypsin on a bare ZnSe surface and on a TiO2 coated ZnSe surface,and the effect of calcium cation strength and ultraviolet light irradiation on the secondary structure of trypsin were also evaluated.FTIR spectra of trypsin showed that Amide I band red shift and AmideⅡband blue shift in aqueous environment on both surfaces compared with the dry trypsin powder,and the addition of calcium cations further changed the Amide bands position,which indicated that the change of the secondary structure could be interfered by the environment.The hydrogen bond formation between water and trypsin,the interaction between surface and trypsin,the interaction between hydrated calcium cations and trypsin,are major facto rs to change the secondary structure of trypsin,and UV light irradiation also showed its influence for the secondary structure.Undesired adsorption of proteins brings big troubles to marine structures.The settled proteins change the physical and chemical properties of the surfaces,which allow marine fouling organisms to settle down on the structures.Therefore,to understand the adsorption mechanism of proteins is very helpful to find an environment-friendly solution against biofouling.Many approaches have been developed to study protein adsorption,but most of them are insufficient to give the chemical interaction information between proteins and surfaces.Fourier transform infrared spectroscopy with attenuated total reflection（FTIR-ATR） is an efficient,fast and non-destructive method for in situ surface measurement,which greatly minimizes the interference of water to infra red spectra,because of the very small depth of penetration of the evanescent wave.In this paper,an in situ FTIR-ATR technology was used to investigate the adsorption process of trypsin on a bare ZnSe surface and on a TiO2 coated ZnSe surface,and the effect of calcium cation strength and ultraviolet light irradiation on the secondary structure of trypsin were also evaluated.FTIR spectra of trypsin showed that Amide I band red shift and Amide Ⅱ band blue shift in aqueous environment on both surfaces compared with the dry trypsin powder,and the addition of calcium cations further changed the Amide bands position,which indicated that the change of the secondary structure could be interfered by the environment.The hydrogen bond formation between water and trypsin,the interaction between surface and trypsin,the interaction between hydrated calcium cations and trypsin,are major facto rs to change the secondary structure of trypsin,and UV light irradiation also showed its influence for the secondary structure.

关 键 词：FTIR-ATR TRYPSIN Secondary structure Adhesion behavior Calcium cation 

分 类 号：X55[环境科学与工程—环境工程] O647.3[理学—物理化学]