title: Lectin activity of the coagulation factor VIII/von Willebrand complex.
abstract: The human coagulation factor VIII (FVIII) is essential in the intrinsic pathway of blood coagulation and circulates mainly as a non-covalently bound complex with the von Willebrand factor (VWF). This complex (FVIII/VWF) protects FVIII from degradation and cellular uptake, although no biological role has been identified yet for this complex. The FVIII/VWF complex was purified from a healthy donor's plasma by affinity chromatography on a Sepharose 4B-Concanavalin A column and was used to determine its capability to interact with erythrocytes and platelets. The purified FVIII/VWF complex at 6.0 and 12 microg/ml agglutinates rabbit and bovine erythrocytes, and showed negative agglutination with erythrocytes from other species including human ABO. Treatment of erythrocytes with Clostridium perfringens sialidase or trypsin increased four-fold the activity toward rabbit erythrocytes and positive agglutination for human A and B erythrocytes, suggesting the presence of FVIII/VWF-cryptic receptors in these erythrocytes. Goat, pig, or human O erythrocytes were not agglutinated even after enzymatic treatment. Fucose or N-acetyl-glucosamine (GlcNAc), at 10 mM, inhibited agglutinating activity of the complex with rabbit, human A and B erythrocytes, whereas galactose and N-acetyl-galactosamine, even at 200 mM, showed no effect on the complex activity. The FVIII/VWF complex, at 1.5 microg/200,000 platelets, significantly decreased platelet aggregation (p < 0.001) when compared with the effect of platelet-rich plasma; this effect was inhibited with 15 mM GlcNAc or fucose. ELISA assays on FVIII/VWF coated polystyrene plates confirmed specific binding to fucose- or biotinylated GlcNAc-dextran derivatives. We therefore propose that the FVIII/VWF complex possesses lectin activity.
authors.affiliation: Biochemistry and Immunology Unit, Technological Institute of Oaxaca, Oaxaca, Mexico.
authors.forename: Francisca
authors.initials: F
authors.lastname: Santizo
authors.forename: Edgar
authors.initials: E
authors.lastname: Zenteno
authors.forename: Socorro
authors.initials: S
authors.lastname: Pina-Canseco
authors.forename: Pedro
authors.initials: P
authors.lastname: Hernandez-Cruz
authors.forename: Margarito Martínez
authors.initials: MM
authors.lastname: Cruz
authors.forename: Laura Perez-Campos
authors.initials: LP
authors.lastname: Mayoral
authors.forename: Eduardo
authors.initials: E
authors.lastname: Pérez-Campos
authors.forename: Ruth
authors.initials: R
authors.lastname: Martínez-Cruz
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000378:metabolism; D005169:Factor VIII / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism* / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D037102:Lectins; D046912:Multiprotein Complexes; D014841:von Willebrand Factor; D005169:Factor VIII