Purification and activation of caprine and canine plasminogens: Comparison with human plasminogen

Abstract

Objective: To unify the purification and activation of plasminogens from three different species, namely: human, caprine and canine.

Materials and methods: Lysine-Sepharose 4B and sephacel DEAE were used, for affinity and ion-exchange chromatography, respectively. The N-terminal sequence was determined for both the intact and degraded plasminogens.

Results: Bands of 92 kDa corresponding to native plasminogens were identified in the three species. Their N-terminal sequences were found to be EPLDDY, DPLDDY and XXLDDY for human, caprine and canine plasminogen, respectively. Furthermore, the degraded in vivo circulating plasminogens from the three species were purified and their N-terminal sequences were KVYLSE, RITLL and RIYLS for the human, caprine and canine, in that order.

Conclusion: Activation of the three plasminogens confirmed the formation of the typical electrophoretic bands for human plasmin corresponding to the heavy A and the light B chains which were also identified in the caprine and canine plasmins. This new purification methodology facilitates the comparison and further elucidation of the fibrinolytic systems in mammals.