[The heterogeneity of streptokinases]

Purified streptokinases of some strains of different types of Strep. pyrogenes (group A) as well as streptokinases of a strain of group C or group G streptococci, resp., were studied in regard of their heterogeneity. Differences of the streptokinases were found in their amino acid compositions and in isoelectric points. Serological differences were detected by a quantitative precipitation reaction with fluorescein-coupled antistreptokinase antisera from the goat as well as by neutralization reactions of the activator activities of the streptokinases by antistreptokinase antisera obtained from guinea pigs.