Summary
1. Methods have been developed for the preparation of factor VII free of prothrombin
and factor X, and of factor X with only a very low contamination with factor VII.
2. Factors VII and X could be found with one stage methods in purified prothrombin
prepared according to Seegers.
3. Purified prothrombin was chromatographed on DE AE-cellulose. Two active fractions
could be eluted, the first with the characteristics of Seegers’ DE AE-Prothrombin,
the second with the characteristics of factor X.
4. It was confirmed that DE AE-Prothrombin does not activate to thrombin in 25% citrate,
and does not generate autoprothrombin C.
5. The combination of both clotting active fractions coming from the DEAE-column restores
the properties of non-chromatographed prothrombin.
6. DE AE-cellulose chromatography of prothrombin does not induce a molecular change
of prothrombin, but separates factor X from prothrombin.
7. Factor X can be activated with tissue thromboplastin-factor VII or with high concentrated
neutral salt solutions to a substance with the biological characteristics of autoprothrombin
C.
8. TAMe activity is generated in factor X preparations after incubation with tissue
thromboplastin and calcium.
9. Factor VII cannot be transformed into autoprothrombin C under the conditions tested.
10. Factor VII is necessary for the activation of factor X with tissue thromboplastin
but not with RVV.
11. The amount of factor X available determines the amount of autoprothrombin C formed,
whereas thromboplastin and factor VII influence the rate of the reaction.
12. The final conclusion is that activated factor X is similar to or identical with
autoprothrombin C.
