Summary
A technic is described for obtaining shadowcast preparations of bovine prothrombin
and thrombin molecules. Three products of prothrombin were investigated. Nonchromatographed
prothrombin and prothrombin chromatographed on Amberlite IRC-50 were homogeneous and
similar in appearance. The mean particle height of IRC-50 prothrombin was less than
that of nonchromatographed prothrombin. In contrast, DEAE cellulose prothrombin products
were heterogeneous, approximately Vs larger and of a more spherical molecular configuration.
The mean particle height of each type of prothrombin preparation was significantly
different from the other. Chromatographic procedures rather than increasing the specific
activity of prothrombin products were detrimental to the molecule and produced measurable
chemical, functional, and morphological modifications.
Three thrombin products were also surveyed. In each case the molecules were discrete
particles and had a smaller mean particle height than prothrombin. On the basis of
the t test, there were no significant differences between the mean particle heights
of IRC-50 thrombin, urea treated thrombin and citrate IRC-50 thrombin. There was no
indication of dimer or trimer configurations in the thrombin preparations.
