title: Sedimentation analysis of von Willebrand and factor VIIIC protein using partition cells in the analytical ultracentrifuge.
abstract: Sedimentation analysis of factor VIII complex was performed in the analytical ultracentrifuge using partition cells. This method allowed for the calculation of three different sedimentation coefficients from each run: one based on ristocetin agglutination activity for von Willebrand protein, SWF; one based on coagulant activity for factor VIIIC, SVIIIC; and one based on the schlieren or adsorption data for protein concentration, Sconc. In most cases, there was no agreement between the three values calculated from the same run, indicating a heterogeneous system. The calculated functional sedimentation coefficients give values that require the molecules to be highly asymmetric to be consistent with a glycoprotein of high molecular weight, which is in agreement with results observed in electron microscope studies. The dissociation of VIIIC into a smaller form can be demonstrated by this method. Determination of the three sedimentation coefficients in a series of fractions from gel filtration indicates a uniform size for the VIIIC activity but not for the WF activity. These observations are in agreement with the concept of a copolymer between WF and VIIIC and also with the concept of separate polymers for the two activities.
mesh_terms: D000941:Antigens / Q000302:isolation & purification*; D001779:Blood Coagulation Factors / Q000302:isolation & purification*; D002850:Chromatography, Gel; D003470:Culture Media; D004727:Endothelium / Q000032:analysis; D005169:Factor VIII / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D010949:Plasma / Q000032:analysis; D014461:Ultracentrifugation / Q000379:methods; D014841:von Willebrand Factor / Q000302:isolation & purification*
chemical_list: D000941:Antigens; D001779:Blood Coagulation Factors; D003470:Culture Media; D046911:Macromolecular Substances; D014841:von Willebrand Factor; D005169:Factor VIII