Homo- and Heterogeneous Forms of Human Factor VIII

Summary

In order to determine the molecular size of human F VIII as found in fresh plasma and as found in fresh-frozen plasma and in cryoprecipitate and to study the relationship of the factor-related properties, namely F VIII:C, F VIIIR:Rcof and F VIIIR:Ag to F VIII, the factor’s elution pattern on Sephacryl 1000 was investigated. When fresh plasma was chromatographed on this gel, F VIII eluted in a single sharp peak with all three F VIII-related activities appearing in the separation range of the gel column. The molecular weight of F VIII was calculated to be higher than 8 × 10⁵. When fresh-frozen plasma was chromatographed on this gel, the elution pattern was identical to that of fresh plasma with the single exception that in several samples F VIII eluted in a broader peak tailing to higher molecular forms. When cryoglobulin fraction of fresh-frozen plasma was chromatographed, F VIII showed distinct heterogenicity in the elution pattern with respect to molecular size and relationship to the F VIII-related properties. Chelation of the endogenous plasma Ca-ions by citrate was found to have no influence on the factor’s elution pattern.

Keywords

Factor VIII - Factor VIII:C - Factor VIIIR:Ag - Factor VIIIR:Rcof - Molecular weight

• References

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