title: Hydrolysis reaction analysis of L-alpha-distearoylphosphatidylcholine monolayer catalyzed by phospholipase A2 with polarization-modulated infrared reflection absorption spectroscopy.
abstract: The hydrolysis reaction of L-alpha-distearoylphosphatidylcholine (DSPC) monolayers catalyzed by phospholipase A2 (PLA(2)) has been studied using polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) with film balance measurements. The PM-IRRAS analysis provides quantitative information about the reaction efficiency at different surface pressures. It was found that the reaction efficiency of L-DSPC monolayer hydrolysis catalyzed by PLA(2) decreased with increasing surface pressure. At zero pressure (lift-off point), the hydrolysis reaction efficiency has the highest value of 45%. Increasing surface pressure leads to the decrease of the hydrolysis efficiency. Since the surface pressure is above 20 mN/m, the hydrolysis reaction nearly stopped. PM-IRRAS technique provides a powerful means to study the hydrolysis process catalyzed by phospholipase A2 at the air/water interface.
authors.affiliation: International Joint Laboratory, Key Laboratory of Colloid and Interface Science, The Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Zhong Guan Cun, Beijing 100080, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wang
authors.forename: Suping
authors.initials: S
authors.lastname: Zheng
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.forename: Gerald
authors.initials: G
authors.lastname: Brezesinski
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
authors.forename: Junbai
authors.initials: J
authors.lastname: Li
mesh_terms: D006868:Hydrolysis; D066298:In Vitro Techniques; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry* / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D013055:Spectrophotometry, Infrared; D013499:Surface Properties
chemical_list: D008563:Membrane Lipids; D010713:Phosphatidylcholines; C010942:1,2-distearoyllecithin; D010741:Phospholipases A; D054467:Phospholipases A2