标题：Exploring the effect of bisphenol S on sludge hydrolysis and mechanism of the interaction between bisphenol S and alpha-Amylase through spectrophotometric methods
作者：Yang, Hang; Hou, Guangying; Zhang, Li; Ju, Lei; Liu, Chunguang
作者机构：[Yang, Hang; Hou, Guangying; Zhang, Li; Liu, Chunguang] Shandong Univ, Sch Environm Sci & Engn, Jinan 250100, Shandong, Peoples R China.; [Ju, Lei] 更多
通讯作者地址：[Liu, CG]Shandong Univ, Sch Environm Sci & Engn, Jinan 250100, Shandong, Peoples R China.
来源：JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
关键词：alpha-Amylase; Sludge hydrolysis; Bisphenol; UV-vis; Three-dimensional; fluorescence spectra; Circular dichroism spectra
摘要：Sewage sludge, as a very significant sources of BPS (up to 523 mg/kg dw) introduction into the environment, must be handled properly. Therefore, it is important to access BPS removal and its effect on sludge treatment with the biological treatment. However, it is unclear for its effect on the hydrolysis of sludge. In this research, impact of BPS on sludge hydrolysis by alpha-Amylase is studied from the respect of component of soluble organic matter in sludge using three-dimensional fluorescence spectra. Enzyme activity assay suggests that sludge hydrolysis is inhibited due to the denaturation of alpha-Amylase with BPS exposure. In order to illuminate the interaction mechanism between BPS and alpha-Amylase, UV-vis, steady-state fluorescence, circular dichroism, synchronous fluorescence, light scattering spectra, enzyme activity assay and molecule docking techniques are applied. Results show that BPS interacts with alpha-Amylase by hydrophobic bond in the activity region of alpha-Amylase. This interaction not only causes an unfolding skeleton structure of alpha-Amylase and a less hydrophobic microenvironment of tyrosine and tryptophan residues, but also leads to a specific fluorophore quenching involving static and dynamic type. This work provides direct evidence about enzyme toxicity of BPS and establishes a new strategy to investigate the interaction between protein and BPS at a molecular level, which is helpful for clarifying the bioactivities of BPS. (C) 2016 Elsevier B.V. All rights reserved.