Comparison of recombinant tissue-type plasminogen activator (rt-PA) expressed in mouse C127 cells and human vascular plasminogen activator (HV-PA).
Tissue-type plasminogen activator produced by recombinant DNA technology (rt-PA) has now been recognized as a promising clot-selective thrombolytic agent. We have compared the properties of rt-PA expressed in mouse C127 cells with those of naturally occurring human vascular plasminogen activator (HV-PA). The molecular weight of HV-PA and rt-PA was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to be approx. 66,000. HV-PA and rt-PA were labile and rapidly lost their activities at pH values below 5.5. The optimum pH of HV-PA and rt-PA for plasminogen activation was around 8.5. HV-PA and rt-PA appeared to be very similar in amidolytic properties, amino-acid composition and carbohydrate composition. Moreover, the N-terminal amino-acid sequence of HV-PA was in good agreement with that of rt-PA. The purified preparations of HV-PA and rt-PA had specific activities of about 250,000 and 600,000 IU/mg, respectively. Both activators bound to fibrin clots to similar degree. In immunodiffusion as well as in the quenching experiments of the fibrinolytic activities, rt-PA appeared to be immunodiffusion as well as in the quenching experiments of the fibrinolytic activities, rt-PA appeared to be immunologically indistinguishable from HV-PA. All these findings indicate that rt-PA expressed in mouse C127 cells is identical with naturally occurring HV-PA in physical and chemical properties.
Hamaguchi
M
M
First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
Takahashi
I
I
Takehara
T
T
Takamatsu
J
J
Saito
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005337:Fibrin / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D005779:Immunodiffusion; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000302:isolation & purification / Q000378:metabolism*
D000596:Amino Acids; D011994:Recombinant Proteins; D005337:Fibrin; D010959:Tissue Plasminogen Activator