Revealing Interfacial Lipid Hydrolysis Catalyzed by Phospholipase A₁ at Molecular Level via Sum Frequency Generation...

The interfacial hydrolysis of phospholipids catalyzed by phospholipase A₁ (PLA1) was studied via sum frequency generation (SFG) vibrational spectroscopy and fluorescence microscopy. Both monolayer and bilayer setups were used to confirm the hydrolysis mechanism. During the hydrolysis, lysophospholipids, one of the hydrolysis products, were desorbed from the interface into the solution, while the other products, fatty acids, self-organized and accumulated with PLA₁ at the interface to form the PLA₁-induced regions, which can serve as nonspecific binding domains for proteins and thus lead to human vascular diseases. This experimental study provides the essential information on revealing the interfacial biochemical process related to the metabolism of the lipids, which is one of the basic building blocks for cells.