title: Crystal structure of human BPI and two bound phospholipids at 2.4 angstrom resolution.
abstract: Bactericidal/permeability-increasing protein (BPI), a potent antimicrobial protein of 456 residues, binds to and neutralizes lipopolysaccharides from the outer membrane of Gram-negative bacteria. At a resolution of 2.4 angstroms, the crystal structure of human BPI shows a boomerang-shaped molecule formed by two similar domains. Two apolar pockets on the concave surface of the boomerang each bind a molecule of phosphatidylcholine, primarily by interacting with their acyl chains; this suggests that the pockets may also bind the acyl chains of lipopolysaccharide. As a model for the related plasma lipid transfer proteins, BPI illuminates a mechanism of lipid transfer for this protein family.
authors.affiliation: UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Beamer
authors.forename: S F
authors.initials: SF
authors.lastname: Carroll
authors.forename: D
authors.initials: D
authors.lastname: Eisenberg
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides; D001665:Binding Sites; D001770:Blood Bactericidal Activity; D001798:Blood Proteins / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D008070:Lipopolysaccharides / Q000378:metabolism; D008565:Membrane Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D010713:Phosphatidylcholines; C021623:bactericidal permeability increasing protein