Quantitative Determination of Plasminogen

Summary

A modification of the caseinolytic assay for plasminogen is described. This assay system is characterized by the following features :

1. Urokinase is used as activator achieving a complete activation of the plasminogen whereas with streptokinase caseinolytically inactive plasminogen-activator complexes are formed.

2. All incubation times are reduced to the minimum which is still compatible with accuracy.

3. Results are expressed in percent of a standard of ten normal plasmas.

4. In this two-stage assay-system (activation of plasminogen to plasmin, digestion of casein by plasmin) both stages proceed simultaneously in the same system, thus the plasmin formed is stabilized “in statu nascendi” by the casein.

5. Several conditions (stability of plasminogen in frozen plasma, use of anticoagulants, reproducibility) are defined.

• References

• 1 Alkjaersig N, Fletcher A. P, Sherry S. The Mechanism of Clot Dissolution by Plasmin. J. clin. Invest 38: 1086 1959;
• 2 Derechin M. Purification of Human Plasminogen. Biochem. J 82: 241 1962;
• 3 Folin O, Ciocalteu V. On Tyrosine and Tryptophane Determination on Protein. J. biol. Chem 73: 627 1927;
• 4 Hagan J. J. In: Roberts H. R, and Geratz G. D. Conference on Thrombolytic Agents. Chicago: 1960: 38.
• 5 Johnson A. J, McCarty W. R, Tillet W. S, Tse A. O, Skoza L, Newman J, Semar M. Fibrinolytic, Caseinolytic and Biochemical Methods for the Study of Thrombolysis in Man: Application and Standardization. In: Tocantins L. M, and Kazal L. A. Blood Coagulation, Hemorrhage and Thrombosis. 449 Grune and Stratton; New York, London: 1964
• 6 Kline D. L. Studies on the purification and activation of plasminogen (Profibrinolysin). Yale J. Biol. Med 26: 365 1954;
• 7 Kline D. L, Fishman J. Proactivator Function of Human Plasmin as shown by Lysine Esterase Assay. J. biol. Chem 236: 2807 1961;
• 8 Lowry O. H, Rosenbrough N. J, Farr A. L, Randall R. J. Protein Measurement with the Folin Phenol Reagent. J. biol. Chem 193: 265 1951;
• 9 Mullertz S. Effect of Carbcxylic and Amino Acids on Fibrinolysis Produced by Plasmin, Plasminogen Activator and Proteases. Proc. Soc. exp. Biol. (N. Y.) 85: 326 1954;
• 10 Norman P. S. Effect of Urea and Methylamine on Plasmin. Proc. Soc. exp. Biol. (N.Y.) 96: 709 1957;
• 11 Remmert L. F, Cohen P. P. Partial Purification and Properties of a Proteolytic Enzyme of Human Serum. J. biol. Chem 181: 431 1949;
• 12 Richard M. N, Sanders B. E. Effect of Lysine and Wetting Agents on Activated Plasminogen Solutions. Canad. J. Biochem 41: 211 1963;
• 13 Shamash Y, Rimon A. The Plasmin Inhibitors of Plasma I. A Method for their Estimation. Thrombos. Diathes haemorrh. (Stuttg.) 12: 119 1964;
• 14 Sherry S, Fletcher A. P, Alkjaersig N, Sawyer W. D. E-aminocaproic Acid: A Potent Inhibitor of Plasminogen Activation. Trans. Ass. Amer. Phycns 72: 62 1959;
• 15 Staprans I, Taylor Jr. F. B. Selective Inhibition of Streptokinase Activation of Plasminogen by Aldehydes. Biochim. biophys. Acta (Amst.) 110: 148 1965;