Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-2-15
pubmed:abstractText
Coagulation factor VIII (FVIII) is a ligand for two members of the low-density lipoprotein receptor family, low-density lipoprotein receptor-related protein (LRP) and low-density lipoprotein receptor, which cooperate in regulating clearance of FVIII from the circulation. This study was aimed to explore the mechanism of interaction of FVIII with very low density lipoprotein receptor (VLDLR), another member of the family, and map receptor-binding sites. Binding of plasma-derived FVIII and its fragments to recombinant soluble ectodomain of VLDLR (sVLDLR) was studied in solid-phase and surface plasmon resonance assays. Full-length FVIII and its light chain bound to sVLDLR with similar affinities (KD = 114 +/- 14 and 95 +/- 11 nmol/l, respectively); in contrast, exposure of high-affinity VLDLR-binding site within the heavy chain (KD = 30 +/- 2 nmol/l) required proteolytic cleavage by thrombin. The VLDLR-binding sites within heavy and light chains were mapped to the A2 domain residues 484-509 and the A3-C1 fragment, based on the inhibitory effects of anti-A2 monoclonal antibody 413 and anti-A3-C1 antibody fragment scFv KM33, respectively, previously shown to inhibit FVIII/LRP interaction. Soluble ligand-binding fragment of VLDLR inhibited activation of factor X by the intrinsic Xase in purified system. In cell culture, a higher Xase activity was associated with wild-type human embryonic kidney cells compared with transfected cells that express VLDLR on the cell surface. We conclude that the binding sites for VLDLR and LRP within FVIII overlap and the A2 site becomes exposed upon physiological activation of FVIII. A functional role of FVIII/VLDLR interaction may be related to regulation of intrinsic Xase activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0957-5235
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
166-77
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
The binding sites for the very low density lipoprotein receptor and low-density lipoprotein receptor-related protein are shared within coagulation factor VIII.
pubmed:affiliation
Center for Vascular and Inflammatory Diseases, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA. NAnanyeva@som.umaryland.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural