Adhesion mechanism of human beta(2)-glycoprotein I to phospholipids based on its crystal structure.Bouma, B., de Groot, P.G., van den Elsen, J.M., Ravelli, R.B., Schouten, A., Simmelink, M.J., Derksen, R.H., Kroon, J., Gros, P.
(1999) EMBO J 18: 5166-5174
- PubMed: 10508150
- DOI: https://doi.org/10.1093/emboj/18.19.5166
- Primary Citation of Related Structures:
- PubMed Abstract:
Human beta(2)-glycoprotein I is a heavily glycosylated five-domain plasma membrane-adhesion protein, which has been implicated in blood coagulation and clearance of apoptotic bodies from the circulation. It is also the key antigen in the autoimmune disease anti-phospholipid syndrome. The crystal structure of beta(2)-glycoprotein I isolated from human plasma reveals an elongated fish-hook-like arrangement of the globular short consensus repeat domains. Half of the C-terminal fifth domain deviates strongly from the standard fold, as observed in domains one to four. This aberrant half forms a specific phospholipid-binding site. A large patch of 14 positively charged residues provides electrostatic interactions with anionic phospholipid headgroups and an exposed membrane-insertion loop yields specificity for lipid layers. The observed spatial arrangement of the five domains suggests a functional partitioning of protein adhesion and membrane adhesion over the N- and C-terminal domains, respectively, separated by glycosylated bridging domains. Coordinates are in the Protein Data Bank (accession No. 1QUB).
Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.