Revealing Interfacial Lipid Hydrolysis Catalyzed by Phospholipase A1 at Molecular-Level Via Sum Frequency Generation Vibrational Spectroscopy and Fluorescence Microscopy

The interfacial hydrolysis of phospholipids (1, 2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) catalyzed by phospholipase A1 (PLA1) was studied via sum frequency generation (SFG) vibrational spectroscopy and fluorescence microscopy. Both the monolayer and bilayer were used to confirm the hydrolysis mechanism. During the hydrolysis, lysophospholipids, one of the hydrolysis products, were desorbed from the interface into the solution, and the other one, fatty acids, self-organized and accumulated with PLA1 at the interface to form the PLA1 induced regions. 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.