Exploring the activation mechanism of alcalase activity with pulsed electric field treatment: Effects on enzyme activity, spatial conformation, molecular dynamics simulation and molecular docking parameters

This study used alcalase derived from Bacillus licheniformis as the research object. We revealed the mechanism by which pulsed electric field (PEF) treatment increases alcalase activity. Alcalase is widely used in the food and brewing industries. The results showed that alcalase activity was increased by 11.26%, α-helix structure was reduced by 18.80%, and the number of hydrogen bonds in the molecule also was decreased from 309 to 305 at 10 kV/cm, which showed that the partial unfolding of the secondary structure was an important factor leading to an increase in alcalase activity. In contrast, fluorescence intensity and ζ-potential were reduced by 61.28% and 17.99%, respectively, and the binding energy between alcalase and casein in molecular docking increased by 15.07%, indicating that the tertiary structure was also a key factor in improving activity. Furthermore, molecular docking technology intuitively reflects that PEF treatment increased alcalase activity.