Ultrasonic enhancement of lipase-catalyzed reactions: Mechanistic
investigation using molecular docking analysis
Abstract
Ultrasound has emerged as an efficient green technology for
intensification of lipase-catalyzed processes. These processes are of
high significance in the context of renewable fuels synthesis. In this
paper, we have attempted to reveal the molecular mechanism of
sonication-induced enhancement of lipase-catalysed reactions. Using
hybrid quantum mechanics/ molecular mechanics computations, we have
initially determined the structure and amino acid composition of the
binding pockets of two common lipase enzyme, viz. CALB and
TLL. Next, these binding pockets were visualized using softwares
PyMOL and VMD to deduce their location in different motifs of the
secondary structure of lipases. Finally, the docking analysis of
different ligands was performed to reveal the amino acid residues
involved for each ligand and the nature of their interactions. Our
results revealed that most of the binding pockets are located in the
α-helix and random coil motifs of enzyme and binding interactions are of
the type hydrogen bond and hydrophobic interactions. Previous literature
reports significant rise in α-helix and random coil contents of lipases
with sonication. This observation concurs with our analysis, and
suggests rise in enzyme activity with sonication due to widening of
catalytic cavity and easier accessibility to binding pockets. Thus, our
analysis provides molecular-level insight into the sonication-induced
enhancement in kinetics and yield of lipase-catalyzed reactions.