title: Modulation of physiological and pathological activities of lysozyme by biological membranes.
abstract: The molecular details of interactions between lipid membranes and lysozyme (Lz), a small polycationic protein with a wide range of biological activities, have long been the focus of numerous studies. The biological consequences of this process are considered to embrace at least two aspects: i) correlation between antimicrobial and membranotropic properties of this protein, and ii) lipid-mediated Lz amyloidogenesis. The mechanisms underlying the lipid-assisted protein fibrillogenesis and membrane disruption exerted by Lz in bacterial cells are believed to be similar. The present investigation was undertaken to gain further insight into Lz-lipid interactions and explore the routes by which Lz exerts its antimicrobial and amyloidogenic actions. Binding and Förster resonance energy transfer studies revealed that upon increasing the content of anionic lipids in lipid vesicles, Lz forms aggregates in a membrane environment. Total internal reflection fluorescence microscopy and pyrene excimerization reaction were employed to study the effect of Lz on the structural and dynamic properties of lipid bilayers. It was found that Lz induces lipid demixing and reduction of bilayer free volume, the magnitude of this effect being much more pronounced for oligomeric protein.
authors.affiliation: Department of Biological and Medical Physics, V. N. Karazin Kharkov National University, 4 Svobody Sq., Kharkov, 61077, Ukraine. valtrusova@yahoo.com
authors.forename: Valeriya
authors.initials: V
authors.lastname: Trusova
mesh_terms: D058227:Amyloidogenic Proteins / Q000378:metabolism / Q000502:physiology; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D057927:Hydrophobic and Hydrophilic Interactions; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism*; D008566:Membranes / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011721:Pyrenes / Q000737:chemistry
chemical_list: D058227:Amyloidogenic Proteins; D008563:Membrane Lipids; D011721:Pyrenes; D009113:Muramidase