The alteration of human and porcine plasmin and the influence of EACA and AMCHA on their activity were investigated. Solutions of both plasmins undergo storage induced alteration, which is best recorded by Chromozym PL, whereas the other chromogenic substrates, S-2251 and S-2302, and casein are less sensitive, and the fibrin plate inadequate. Plasmin amidolytic and fibrinolytic activity is maximally enhanced at 7.6 × 10–3 M EACA and 6.4 × 10–4 M AMCHA, and decay through storage is reversed. The caseinolytic activity seems slightly inhibited at the same EACA and AMCHA concentrations.
Our results show:
1. The quotient: plasmin activity towards Chromozym PL/Activity towards S-2251 is a useful indicator of "plasmin quality". The quotient decreases markedly upon storage of plasmin solutions.
2. Plasmin stability is improved in the presence of AMCHA.
3. It is valueless to add EACA or AMCHA to inhibit plasmin in amidolytic assays since the chosen concentration enhances the amidolytic activity of already formed plasmin.
2
Gaffney PJ,
Miller-Andersson M,
Kirkwood TB L.
Unreliability of chromogenic substrates for assay of the clotting activity of thrombin. Haemostasis 1978; 7: 109-112
3
Celander DR,
Messer D,
Mason GuestM.
The fibrinolytic system: A review of its therapeutic significance and control with particular emphasis on its inhibition by epsilon-aminocaproic acid. Tex Rep Biol Med 1961; 19: 16-27
5
Thorsen S,
Astrup T.
Substrate composition and the effect of epsilon-aminocaproic acid on tissue plasminogen activator and urokinase-induced fibrinolysis. Thrombos diathes haemorrh 1974; 32: 306-324
6
Ablondi FB,
Hagan JJ,
Philips M,
De Renzo EC.
Inhibition of plasmin, trypsin and the streptokinase-activated fibrinolytic system by epsilon-aminocaproic acid. Arch Biochem Biophys 1959; 82: 153-160
7
Ambrus CM,
Ambrus JL,
Lassman HB,
Mink IB.
On the heterogeneity of activity by various types of plasmins and the spectra of inhibition of some plasmin inhibitors. Res Commun Chem Pathol Pharmacol 1970; 1: 67-85
10
Thorsen S,
Kok P,
Astrup T.
Reversible and irreversible alterations of human plasminogen indicated by changes in susceptibility to plasminogen activators and in response to epsilon-aminocaproic acid. Thrombos Diathes haemorrh 1974; 32: 325-340
12
Fukutake K,
Shida K,
Arakawa T,
Kato K.
Analysis of fibrinolysis by the use of epsilon-aminocaproic acid: Preliminary report. Blood 1960; 15: 690-697
13
Markus G,
De Pasquale JL,
Wissler FC.
Quantitative determination of the binding of epsilon-aminocaproic acid to native plasminogen. J Biol Chem 1978; 253: 727-732
14
Markus G,
Priore RL,
Wissler FC.
The binding of tranexamic acid to native (Glu) and modified (Lys) human plasminogen and its effect on conformation. J Biol Chem 1979; 254: 1211-1216
