[Studies of the heterogeneity of streptokinases of different origin (author's transl)]

Streptokinases of six different strains of group A streptococci (Strep. pyogenes), and of one strain each of streptococcal groups C and G were isolated from supernatants of the cultures. The purified or partial purified streptokinases were characterized by electrophoresis in agar-acrylamidgels, isoelectric focussing in acrylamide gel and by determinations of the molecular weights by means of sodium dodecylsulphate acrylamide electrophoresis and gel filtration on sephadex G-100. Furtheron these streptokinases were compared serologically using human antistreptokinase-antiserum. It was found that all of the streptokinases examined in this study were different in their isoelectric points (5.05-6.5) and that they showed serological cross-reactions. The molecular weights are not significantly different and were determined to about 45 000 daltons.