APSAC is an anisoylated human plasminogen-streptokinase complex useful in the
treatment of myocardial infarct. Its reported advantages over other existing thrombolytics
such as alteplase and streptokinase include a longer half life, ease of administration, and a
more specific local antithrombotic effect.
Preparation of freeze dried p-anisoyl streptokinase/plasminogen complex
without internal peptide bond cleavages:
Streptokinase (250,000 units, Kabi, Stockholm, Sweden) was dissolved in 0.1
M trishydroxymethylmethane hydrochloride pH 7.4 (2.5 ml) and a solution of
0.1 M p-amidinophenyl p'-anisate in dimethylsulphoxide (0.25 ml) added. A
slight cloudiness resulted. To this mixture was added 0.5 ml of a solution of
human lys-plasminogen (8.99 mg/ml in the above buffer) [Kabi, Stockholm]
and the solution was thoroughly and rapidly mixed. After standing on ice for
15 minutes, the solution was stored on ice until use. After approximaely 2
hours 0.4 ml (40,000 units) of the material was diluted with 3.0 ml of a slurry
of L-lysine-sepharose 4B (a 33% wet wt/volume suspension in the above
buffer) and stood at 0°C for 1 hour. The gel was filtered on a glass sinter funnel at 4°C under suction and washed with the buffer (100 ml). The gel was
eluted under gentle suction with the same buffer containing 0.1 M ε-
aminocaproic acid (3 lots of 5 ml). The combined filtrates were dialysed for 2
hours at 4°C against ammonium bicarbonate buffer (50 mM pH 7.0)
containing 2.5% w/v mannitol. The product was then freeze dried to 0.799 g
of a white solid. Approximately 195 mg of this material was analysed by slab
gel polyacrylamide gel electrophoresis using 10% w/v gels in the presence of
sodium dodecyl sulphate. Two main polypeptide bands were observed
corresponding to lys-plasminogen (m.w. 84,000) and streptokinase (m.w.
47,000). There was also a trace of contaminating human serum albumin
derived from the commercial streptokinase preparation.
