von Willebrand factor binds to native collagen VI primarily via its A1 domain
| Autor: | Ingrid Vreys, Jos Vermylen, Hiroshi Yamamoto, Hans Deckmyn, Katarine Nuyts, Marc Hoylaerts |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
Blood Platelets
congenital hereditary and neonatal diseases and abnormalities Invertebrate Hormones Placenta Biochemistry law.invention Cell Line Extracellular matrix Von Willebrand factor Collagen VI law Pregnancy hemic and lymphatic diseases von Willebrand Factor Humans Platelet Binding site Salivary Proteins and Peptides Molecular Biology Lung Binding Sites biology Chemistry Aurintricarboxylic Acid Antibodies Monoclonal Cell Biology Fibroblasts Molecular biology Recombinant Proteins Extracellular Matrix Kinetics Recombinant DNA biology.protein cardiovascular system Chromatography Gel Platelet aggregation inhibitor Female Invertebrate hormone Collagen Platelet Aggregation Inhibitors circulatory and respiratory physiology Research Article |
| Zdroj: | Europe PubMed Central |
| Popis: | Collagen VI is abundant in the arterial subendothelium. To investigate its mechanism of interaction with von Willebrand factor (vWF), collagen VI was isolated from human placenta and from the extracellular matrix of the human lung fibroblast cell line MRC-5. Purified vWF bound to non-digested collagen VI with moderately high affinity (EC50 ≈ 5 nM) and could be inhibited by the Hirudo medicinalis collagen inhibitor calin. The anti-(human vWF A1 domain) monoclonal antibody (AJvW-2), as well as aurin tricarboxylic acid (ATA), at concentrations that saturate the vWF A1 domain, also inhibited this binding. In contrast, the monoclonal anti-(human vWF A3 domain) antibody (82D6A3) inhibited vWF binding to collagens I, III and IV, but had no effect on vWF binding to collagen VI. Likewise, vWF binding to collagen VI was not inhibited by the recombinant vWF domain D4. Polyclonal anti-(collagen VI) antibodies, specifically neutralizing the binding of vWF to collagen VI, confirmed that in the intact endothelial cell extracellular matrix, collagen VI was accessible for interaction with vWF. This binding was only marginally affected by 82D6A3 but was dose-dependently inhibited by AJvW-2, ATA and the A1 domain analogue VCL (recombinant A1 domain of vWF), with IC50 values comparable to those found for the inhibition of vWF binding to isolated collagen VI. The weak interaction of isolated human platelets with collagen VI was mediated via the platelet collagen receptor (GPIa/IIa) and was competitively inhibited by vWF but not by VCL, suggesting that vWF and GPIa/IIa bind to neighbouring but distinct sites on collagen VI. We conclude that vWF binds to collagen VI primarily via its A1 domain, which distinguishes it from the vWF A3 domain-mediated binding to fibrillar collagens. |
| Databáze: | OpenAIRE |
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