Abstract

Enzymes are widely applied to the processes of leather making and play an important role in promoting the green development of this industry. Various surfactants are common adjuvents to quicken up the course of leather making. In this paper, UV spectroscopy, circular dichroism and molecular docking were used to investigate the mechanism by which the interactions of sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB) and fatty alcohol polyoxyethylene ether (Peregal (O-20)) respectively influence the bioactivity and the conformation of EMPr protease. The results for EMPr activity demonstrate that the bioactivity of EMPr was restrained in CTAB or Peregal (O-20) solutions. SDS at low concentrations can slightly increase the activity of EMPr. When the concentration of SDS was over 0.5mmol/L, the activity was also inhibited. The bands of the UV and circular dichroism spectra show that the secondary structure of EMPr was damaged by the three surfactants respectively. Molecular docking results show that hydrogen bonds and hydrophobic interactions were found in the three surfactant-EMPr complexes. This study presents insights into the interactions of surfactants with EMPr from the molecular level to comprehend how surfactants affect the bioactivity and conformation of EMPr in complex leather making processes