Purification of Factor VII from bovine plasma. Reaction with tissue factor and activation of Factor X.

Factor VII has been purified up to 330,000-fold from bovine plasma by adsorption on, and elution from, barium sulfate, anion exchange chromatography, gel filtration, and affinity chromatography on benzamidine coupled to Sepharose. The purified material is inhibited by diisopropylphosphorofluoridate both in its native state and after the formation of a complex with tissue factor in the presence of calcium ions. The Factor VII-tissue factor complex, unlike native Factor VII, has coagulant activity; this activity results in a complex proteolytic activation of Factor X to X,, as shown by gel electrophoresis in the presence of sodium dodecyl sulfate, and by assay of the Factor X, produced. It has been concluded that Factor VII, unlike Factor X and prothrombin, circulates in the plasma as an active enzyme which has an absolute requirement for tissue factor in order to develop proteolytic activity towards Factor X.