New Insights into the Toxicity of n-Butanol to Trypsin: Spectroscopic and Molecular Docking Descriptions

n-Butanol has been widely used and its residue exists extensively in the environment. It could lead to conformational and functional changes of trypsin by forming a complex with it. Docking method and spectrographic technique were employed to the study of the complex of trypsin and n-butanol. The fluorescence results indicated that n-butanol can form a complex with trypsin and change the distance between tryptophan and fluorescence quenchers. The conformational changes of trypsin were proved by UV-visible absorption and synchronous fluorescence spectroscopy indicating that n-butanol had little effect on the conformation of trypsin at a low concentration while denatured and coagulated the trypsin at a high concentration. The binding site was displayed by molecular modeling, which gave information about distances and binding forces between n-butanol and trypsin. The results were in accordance with spectroscopic experiments. Besides, enzyme activity assay gave the dose-response relationship of n-butanol with trypsin.