Comparative analysis of the activity and content of different streptokinase preparations.
OBJECTIVE
The dosage of fibrinolytic agents such as streptokinase must be controlled carefully to maximize therapeutic activity while avoiding adverse effects. Therefore, the integrity and activity of streptokinase products is likely to be clinically relevant. This study was conducted to compare the in vitro characteristics of different streptokinase preparations.


RESULTS
Sixteen streptokinase preparations (three of which were recombinant) were compared in a chromogenic substrate activity assay by native, and reducing, sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE), and N-terminal sequencing. Deficiencies in streptokinase activity were observed in most of the products: only three fulfilled the minimum requirements of the European Pharmacopoeia. These were Icikinase (ICI Pharm Ltd, India, only one of two batches tested), Kabikinase (Pharmacia Upjohn, Sweden), and Streptase (Aventis Behring GmbH, Germany). The remaining products exhibited activities ranging from 20.8 to 86.6% of the label claim. Differences in composition and purity were demonstrated by both native and reducing SDS-PAGE. N-terminal sequencing of the recombinant preparations showed differences compared with the native protein--indeed, for one product, the 15 N-terminal amino acids bore no resemblance to streptokinase.


CONCLUSIONS
There are wide variations in the activity, purity, and composition of the available streptokinase preparations.
Hermentin
Peter
P
ZLB Behring GmbH, P.O. Box 1230, 35002 Marburg, Germany.
Cuesta-Linker
Thomas
T
Weisse
Joerg
J
Schmidt
Karl-Heinz
KH
Knorst
Marion
M
Scheld
Michael
M
Thimme
Michael
M
D004591:Electrophoresis, Polyacrylamide Gel; D005343:Fibrinolytic Agents / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D011994:Recombinant Proteins / Q000737:chemistry / Q000493:pharmacokinetics; D013300:Streptokinase / Q000737:chemistry* / Q000493:pharmacokinetics; D013810:Therapeutic Equivalency
D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D013300:Streptokinase