| Popis: |
Autoprothrombin III (Factor X) was separated from purified bovine prothrombin complex by chromatography on DEAE-cellulose and filtration through a Sephadex G-100 column. It had the same amino acid composition and approximately the same sedimentation characteristics in the ultracentrifuge as the first product obtained in this laboratory. The sedimentation constant was 3.58S. The product was studied by disc gel electrophoresis over a wide pH range. It was free of autoprothrombin C (Factor Xa), was stable, and had no tendency to activate spontaneously. On the basis of 27 Sephadex filtration experiments, the molecular weight was 81,900 ± 2,770. For autoprothrombin C, it was 53,500; by another method, it was 58,000. The N-terminal amino acids were alanine and serine, while those for autoprothrombin C were glycine and serine. Peptide maps for the zymogen and enzyme were similar except there were fewer peptides on the map of the latter. Based on a specific activity of 1,200 u/mg and a plasma concentration of 30 u/ml, the concentration of autoprothrombin III in bovine plasma most likely ranges from 2–3 mg%. |
