Ultracentrifugation of Acetylated Thrombin^[*]

Summary

Acetylated bovine thrombin with a specific activity of 5930 units per milligram dry weight was found to be homogeneous by ultracentrifuge analysis. The sedimentation constant in units of 10⁻¹³ sec. at 20° C, in 0.1 M potassium chloride was 3.3. This constant is not concentration dependent.

^* This investigation was supported by a research grant H-3424 from the National Heart Institute, National Institutes of Health, U.S. Public Health Service.

• References

• (1) Landaburu R. H, Seegers W. H. Further studies of prothrombin derivatives. Proc. Soc. exp. Biol. Med. (N. Y.) 94: 708 1957;
• (2) Landaburu R. H, Seegers W. H. The generation of proteolytic activity during the activation of prothrombin. Amer. J. Physiol. 197: 1178 1959;
• (3) Seegers W. H, Andrews E. B, McClaughry R. I. Formation of prothrombin derivatives from purified prothrombin. Amer. J. Physiol. 164: 722 1951;
• (4) Seegers W. H, Thomas W. R, Landaburu R. H, Mammen E. F. Prothrombin: Living enzyme of my blood. Rec. chem. Progress.. In press.
• (5) Seegers W. H, Landaburu R. H, Johnson J. F. Thrombin-E as a fibrinolytic enzyme. Science 131: 126 1960;
• (6) Seegers W. H, Levine W. G, Shepard R. S. Further studies on the purification of thrombin. Canad. J. Biochem. 36: 603 1958;
• (7) Landaburu R. H, Seegers W. H. The activation of thrombin. Canad. J. Biochem. 37: 1362 1959;
• (8) Seegers W. H, Casillas G, Shepard R. S, Thomas W. R, Halick P. Some properties of thrombin preparations. Canad. J. Biochem. 37: 775 1959;