title: CNS myelin structural modification induced in vitro by phospholipases A2.
abstract: Myelin is the self-stacked membrane surrounding axons; it is also the target of several pathological and/or neurodegenerative processes like multiple sclerosis. These processes involve, among others, the hydrolytic attack by phospholipases. In this work we describe the changes in isolated myelin structure after treatment with several secreted PLA2 (sPLA2), by using small angle x-ray scattering (SAXS) measurements. It was observed that myelin treated with all the tested sPLA2s (from cobra and bee venoms and from pig pancreas) preserved the lamellar structure but displayed an enlarged separation between membranes in certain zones. Additionally, the peak due to membrane asymmetry was clearly enhanced. The coherence length was also lower than the non-treated myelin, indicating increased disorder. These SAXS results were complemented by Langmuir film experiments to follow myelin monolayer hydrolysis at the air/water interface by a decrease in electric surface potential at different surface pressures. All enzymes produced hydrolysis with no major qualitative difference between the isoforms tested.
authors.affiliation: Departamento de Química Biológica-CIQUIBIC (CONICET), Facultad de Ciencias Químicas, Universidad de Nacional de Córdoba, Haya de la Torre S/N, X5000HUA, Córdoba, Argentina.
authors.forename: Pablo J
authors.initials: PJ
authors.lastname: Yunes Quartino
authors.affiliation: Departamento de Química Biológica-CIQUIBIC (CONICET), Facultad de Ciencias Químicas, Universidad de Nacional de Córdoba, Haya de la Torre S/N, X5000HUA, Córdoba, Argentina.
authors.forename: Julio M
authors.initials: JM
authors.lastname: Pusterla
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), FaMAF, Universidad Nacional de Córdoba, Argentina.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Galván Josa
authors.affiliation: Departamento de Química Biológica-CIQUIBIC (CONICET), Facultad de Ciencias Químicas, Universidad de Nacional de Córdoba, Haya de la Torre S/N, X5000HUA, Córdoba, Argentina.
authors.forename: Gerardo D
authors.initials: GD
authors.lastname: Fidelio
authors.affiliation: Departamento de Química Biológica-CIQUIBIC (CONICET), Facultad de Ciencias Químicas, Universidad de Nacional de Córdoba, Haya de la Torre S/N, X5000HUA, Córdoba, Argentina. Electronic address: oliveira@fcq.unc.edu.ar.
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Oliveira
mesh_terms: D000388:Air / Q000032:analysis; D000818:Animals; D001514:Bee Venoms / Q000737:chemistry / Q000201:enzymology; D001516:Bees; D002417:Cattle; D004546:Elapid Venoms / Q000737:chemistry / Q000201:enzymology; D017815:Elapidae; D006868:Hydrolysis; D007527:Isoenzymes / Q000737:chemistry* / Q000302:isolation & purification; D009186:Myelin Sheath / Q000737:chemistry* / Q000648:ultrastructure; D010179:Pancreas / Q000737:chemistry / Q000201:enzymology; D054467:Phospholipases A2 / Q000737:chemistry* / Q000302:isolation & purification; D053838:Scattering, Small Angle; D012996:Solutions; D013116:Spinal Cord / Q000737:chemistry*; D013499:Surface Properties; D013552:Swine; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001514:Bee Venoms; D004546:Elapid Venoms; D007527:Isoenzymes; D012996:Solutions; D014867:Water; D054467:Phospholipases A2
keywords: Demyelination; Langmuir monolayers; Myelin; Phospholipases; Saxs