Structural investigations of pneumolysin/lipid complexes.
Pneumolysin, a virulence factor from the human pathogen Streptococcus pneumoniae, is a water-soluble protein which forms ring-shaped oligomeric structures upon binding to cholesterol-containing lipid membranes. It induces vesicle aggregation, membrane pore formation and withdrawal of lipid material into non-bilayer proteolipid complexes. Solid-state magic angle spinning and wideline static NMR, together with freeze-fracture electron microscopy, are used to characterize the phase changes in fully hydrated cholesterol-containing lipid membranes induced by the addition of pneumolysin. A structural model for the proteolipid complexes is proposed where a 30-50-meric pneumolysin ring lines the inside of a lipid torus. Cholesterol is found to be essential to the fusogenic action of pneumolysin.
Bonev
B
B
Biomembrane Structure Unit, Biochemistry Department, University of Oxford, UK.
Gilbert
R
R
Watts
A
A
D001426:Bacterial Proteins; D005614:Freeze Fracturing; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008561:Membrane Fusion; D008563:Membrane Lipids / Q000737:chemistry*; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D013296:Streptococcus pneumoniae / Q000737:chemistry / Q000472:pathogenicity; D013301:Streptolysins / Q000737:chemistry* / Q000633:toxicity
D001426:Bacterial Proteins; D008563:Membrane Lipids; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae