Study On The Conformation Changes Of Several Antimicrobial Antimicrobials And Pollutants

The pharmacological studies of anti-inflammatory and antimicrobial agents have been widely concerned by scientific researchers at home and abroad.They can be entered into the body through diet,respiration and skin contact,and interact with biological macromolecules such as proteins directly and indirectly.So they will affect the function and nature of the protein and harm to the human body.The mechanism between their active ingredient and protein is the research hotspot of modern medicine,chemistry and biology.Proteins carry the functions of life activities and have a leading role in life activities.They can be reversibly combined with varieties of exogenous drugs and contaminants.Therefore,the effect of these small molecules on protein conformational changes is one of the most important issues in chemistry field.In recent years,fluorescence analysis has attracted more and more attention from chemical researchers because of its important application value in chemical detection and biological sample analysis.At present,the researchers have done lots of studies about small molecules on the impact of protein conformation changes,but the more in-depth explanation of its mechanism is not yet perfect.Therefore,the in-depth study of the small molecule and protein binding mechanism is still a meaningful work.In summary,the main contents of this paper are as follows: 1.Three representative imidazoles derivatives of 1-(4-bromophenyl)-2,4,5-triphenyl-1H-imidazole(4-fluorophenyl)-4,5-diphenyl-1H-imidazole(BFDI)and 1-(4-bromophenyl)-4,5-diphenyl-2-(thiophen-2-yl)pyridin-2-yl)-1H-imidazole(BDTI)were designed and synthesized.The interaction mechanism between three kinds of imidazole derivatives and human serum albumin was studied by spectroscopy and molecular docking.The structural characteristics of the interaction were investigated.The enthalpy change andentropy change were calculated by thermodynamic data.The binding distance was calculated by the non-radiative energy transfer methods.Finally,the effect of BPTI/BFDI/BDTI on the conformation of human serum protein was confirmed by infrared spectroscopy and circular dichroism.2.The interaction between triclosan(TCS)and trichlorocarban(TCC)and pepsin were studied by fluorescence spectroscopy,UV-vis absorption spectroscopy,infrared spectroscopy and molecular simulation.The effects of TCS/TCC and pepsin on the secondary structure of pepsin were quantitatively analyzed.The force type of TCS/TCC and pepsin were determined by thermodynamic parameters.Finally,molecular modeling was used to determine the binding position of TCS/TCC to pepsin.3.The binding ability of perfluorooctanoic acid(PFOA)and perfluorononanoic acid(PFNA)to pepsin was studied by spectroscopic method and molecular docking method,and their binding ability to pepsin was compared.At the same time,the quenching mechanism of PFOA/PFNA and pepsin were confirmed by time-resolved fluorescence,and the main force types were analyzed by thermodynamic parameters.In addition,the conformation of pepsin was also explained though UV-vis,FT-IR and three-dimensional fluorescence.Finally,the experimental results were confirmed by circular dichroism and molecular docking.