title: Biophysical studies of the interactions between the phage varphiKZ gp144 lytic transglycosylase and model membranes.
abstract: The use of naturally occurring lytic bacteriophage proteins as specific antibacterial agents is a promising way to treat bacterial infections caused by antibiotic-resistant pathogens. The opportunity to develop bacterial resistance to these agents is minimized by their broad mechanism of action on bacterial membranes and peptidoglycan integrity. In the present study, we have investigated lipid interactions of the gp144 lytic transglycosylase from the Pseudomonas aeruginosa phage varphiKZ. Interactions with zwitterionic lipids characteristic of eukaryotic cells and with anionic lipids characteristic of bacterial cells were studied using fluorescence, solid-state nuclear magnetic resonance, Fourier transform infrared, circular dichroism, Langmuir monolayers, and Brewster angle microscopy (BAM). Gp144 interacted preferentially with anionic lipids, and the presence of gp144 in anionic model systems induced membrane disruption and lysis. Lipid domain formation in anionic membranes was observed by BAM. Gp144 did not induce disruption of zwitterionic membranes but caused an increase in rigidity of the lipid polar head group. However, gp144 interacted with zwitterionic and anionic lipids in a model membrane system containing both lipids. Finally, the gp144 secondary structure was not significantly modified upon lipid binding.
authors: Département de Chimie, Regroupement Québécois de Recherche sur la Fonction, la Structure et l'Ingénierie des Protéines (PROTEO), Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, Quebec, QC, G1V 0A6, Canada.
authors: Isabelle
authors: I
authors: Cloutier
authors: Catherine
authors: C
authors: Paradis-Bleau
authors: Anne-Marie
authors: AM
authors: Giroux
authors: Xavier
authors: X
authors: Pigeon
authors: Marjolaine
authors: M
authors: Arseneault
authors: Roger C
authors: RC
authors: Levesque
authors: Michèle
authors: M
authors: Auger
mesh_terms: D002942:Circular Dichroism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D005452:Fluoresceins / Q000737:chemistry; D005453:Fluorescence; D016695:Glycosyltransferases / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010715:Phosphatidylglycerols / Q000737:chemistry; D011487:Protein Conformation; D017105:Pseudomonas Phages / Q000737:chemistry* / Q000201:enzymology*; D011550:Pseudomonas aeruginosa; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D053835:Unilamellar Liposomes / Q000737:chemistry; D014732:Vibration
chemical_list: D005452:Fluoresceins; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010715:Phosphatidylglycerols; D053835:Unilamellar Liposomes; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; C002773:dimyristoylphosphatidylglycerol; D016695:Glycosyltransferases; D004134:Dimyristoylphosphatidylcholine; C007740:fluorexon