title: Surface mixing of products and substrate of PLA₂ in enzyme-free mixed monolayers reproduces enzyme-driven structural topography.
abstract: It was proposed that topographic changes in lipid monolayers hydrolyzed by lipolytic enzymes such as Phospholipase A2 (PLA2) are a consequence of enzyme activity at the surface. Lateral packing defects that arise from lipid phase coexistence were suggested as places at which PLA2 activity is preferably localized. Our work employs a method for mixing two lipid monolayers in order to simulate lipid mixing of products and substrate at the surface in the absence of enzyme. In such enzyme-free mixed films, a topographic pattern similar to that actively generated by PLA2 is observed. The main conclusion from our experiments is that mixing-demixing properties of substrate and products generated by PLA2 can determine the evolution of the surface topography.
authors.affiliation: Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina. luisinadetullio@mail.fcq.unc.edu.ar
authors.forename: Luisina
authors.initials: L
authors.lastname: De Tullio
authors.forename: María L
authors.initials: ML
authors.lastname: Fanani
authors.forename: Bruno
authors.initials: B
authors.lastname: Maggio
mesh_terms: D000818:Animals; D002232:Carbocyanines; D005456:Fluorescent Dyes; D006868:Hydrolysis; D007700:Kinetics; D008856:Microscopy, Fluorescence; D010713:Phosphatidylcholines / Q000737:chemistry*; D054467:Phospholipases A2 / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D013552:Swine
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D010713:Phosphatidylcholines; D012996:Solutions; C097511:didodecylindocarbocyanine; D054467:Phospholipases A2
keywords: Dipalmitoylphosphatidylcholine; Lipid domain morphology; Lipid monolayer; Porcine pancreas phospholipase A(2); Surface mixing