Sedimentation analysis of von Willebrand and factor VIIIC protein using
partition cells in the analytical ultracentrifuge
GH Barlow, SE Martin and VJ Marder
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.
Volume 63,
Issue 4,
pp. 940-943,
04/01/1984
Copyright © 1984 by The American Society of Hematology
