title: Native and dry-heated lysozyme interactions with membrane lipid monolayers: Lipid packing modifications of a phospholipid mixture, model of the Escherichia coli cytoplasmic membrane.
abstract: Antimicrobial resistance is currently an important public health issue. The need for innovative antimicrobials is therefore growing. The ideal antimicrobial compound should limit antimicrobial resistance. Antimicrobial peptides or proteins such as hen egg white lysozyme are promising molecules that act on bacterial membranes. Hen egg white lysozyme has recently been identified as active on Gram-negative bacteria due to disruption of the outer and cytoplasmic membrane integrity. Furthermore, dry-heating (7 days and 80 °C) improves the membrane activity of lysozyme, resulting in higher antimicrobial activity. These in vivo findings suggest interactions between lysozyme and membrane lipids. This is consistent with the findings of several other authors who have shown lysozyme interaction with bacterial phospholipids such as phosphatidylglycerol and cardiolipin. However, until now, the interaction between lysozyme and bacterial cytoplasmic phospholipids has been in need of clarification. This study proposes the use of monolayer models with a realistic bacterial phospholipid composition in physiological conditions. The lysozyme/phospholipid interactions have been studied by surface pressure measurements, ellipsometry and atomic force microscopy. Native lysozyme has proved able to absorb and insert into a bacterial phospholipid monolayer, resulting in lipid packing reorganization, which in turn has lead to lateral cohesion modifications between phospholipids. Dry-heating of lysozyme has increased insertion capacity and ability to induce lipid packing modifications. These in vitro findings are then consistent with the increased membrane disruption potential of dry heated lysozyme in vivo compared to native lysozyme. Moreover, an eggPC monolayer study suggested that lysozyme/phospholipid interactions are specific to bacterial cytoplasmic membranes.
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France. Electronic address: melanie.derde@agrocampus-ouest.fr.
authors.forename: Melanie
authors.initials: M
authors.lastname: Derde
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Nau
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Guérin-Dubiard
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Lechevalier
authors.affiliation: Université de Rennes 1, Institut de physique de Rennes, UMR6251, CNRS, F-35042 Rennes, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Paboeuf
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Jan
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Baron
authors.affiliation: Agrocampus Ouest, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France; INRA, UMR1253 Science et technologie du lait et de l'œuf, F-35042 Rennes, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Gautier
authors.affiliation: Université de Rennes 1, Institut de physique de Rennes, UMR6251, CNRS, F-35042 Rennes, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Vié
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D006358:Hot Temperature; D007700:Kinetics; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D008563:Membrane Lipids; D010743:Phospholipids; D009113:Muramidase
keywords: Antimicrobial protein; Cytoplasmic membrane; Dry-heating; Escherichia coli; Monolayer membrane model