Crystal structure of human BPI and two bound phospholipids at 2.4 angstrom resolution
Beamer, L.J.; Carroll, S.F.; Eisenberg, D.
Science 276(5320): 1861-1864
1997
ISSN/ISBN: 0036-8075 PMID: 9188532 Document Number: 474164
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. Copyright 1997 by the AAAS.