A subclass of esterases, lipase is an enzyme that catalyzes the hydrolysis and formation of lipids. While produced in the pancreas, it is also present in the stomach and mouth. Due to its effective ester bond hydrolysis of lipids, lipase is essential for fat digestion, breaking lipids into monoglycerides and single fatty acids.
The quaternary structure of horse pancreatic lipase (as featured right) contains two molecules which each contain 449 amino acid residues, 705 water molecules, and 2 calcium ions. These two identical molecules are connected by a two-fold symmetry axis.
The of lipase (just one subunit) include 102 residues which create 13 alpha helices, shown in black, and 139 residues involved in beta sheets totaling 28 strands, shown in red. Lipase of course consists of both
The of lipase are shown in yellow. Most of the hydrophobic regions are buried deep in the molecule so as to reduce interactions with water.
The most prominent ligand involved in the structure of lipase is the . This ion has been shown to promote the folding of lipase into its active dimer state.
