Structure of human BPI (bactericidal/permeability-increasing protein) and implications for related proteins.

Human bactericidal/permeability-increasing protein (BPI) belongs to a family of mammalian lipopolysaccharide-binding and lipid transport proteins. Recent sequence database searches indicate that several other protein families, including the palate, lung and nasal epithelial clone (PLUNC), parotid secretory protein (PSP) and BPI-like proteins, are likely to share the BPI fold, which was determined through X-ray crystallographic studies. As the single representative of its fold family of known structure, the three-dimensional model of BPI suggests structural features that are likely to be conserved across this large and varied group of proteins.