Substrate specificity of tissue plasminogen activator and urokinase as determined with synthetic chromogenic substrates.

Abstract

Three different synthetic chromogenic substrates (H glutamylglycyl-L-argnine p-nitroanilide (S-2227), pyro-glutamyl-glycyl-L-argininep-nitroanilide (S-2444), and H D-isoleucyl-L-prolyl-L-arginine p-nitroanilide (S-2288)) were investigated for use in the measurement of plasminogen activator activity with high molecular weight urokinase (H-UK), low molecular weight urokinase (L-UK), and tissue plasminogen activator (TPA). The three substrates were hydrolyzed by both TPAtype and UK-type plasminogen activator. As regards the amidolytic activity of S-2227, TPA exhibited a weaker amidolytic activity, and L-UK a stronger activity. In the case of the amidolytic activity of S-2444, no great difference between the three activators was observed in terms of Vmax. As regards the amidolytic activity of S-2288, L-UK exhibited a stronger activity, and TPA a weaker activity. It is suggested that the molecular size of the synthetic chromogenic substrate was too small when compared to natural substrate (fibrin), and therefore that fibrin-binding sites around the catalytic site in TPA are not recognized.

Yield improvement for manufacture of α1‐proteinase inhibitor

“…Azocaseinolysis was assayed at 5 ° C and pH 8·1 or 9·3 by standard procedure [6]; linear kinetics were obtained during the time course of the assay. Amidolysis was assayed at 0 ° C and at pH 8·1 or 9·3 using S-2288 (DiaPharma Group, Inc., Franklin, OH) as substrate [7]; linear kinetics were obtained during the time course of the assay. Only freshly prepared IV-1 suspensions, resulting from 1-to 2-h dissolution of IV-1 paste, were assayed for azocaseinolysis or for amidolysis.…”

Ativadores de plasminogenio do tipo uroquinase, extraídos de plasma bovino por precipitação com sulfato de celulose

“…A m idolytic assays were carried out with the solution containing the plasminogen activator, as well as with the most fibrinolytic active plasminogen activator, according to Frieberger* (1982). S-2444 (L-pyroglutamyl-glycyl-L-arginine-p-nitroanilide) (ORTHO-DIAGNOSTICS), which is UK-specific according to Matsuo et al'* (1983), was used as chromogenic substrate.…”

Plasminogen Activator in Bronchoalveolar Fluid

“…pH 8.4. with 0.1 M NaCl, and reacted at 37 "C with 50 pi of 1 mM S-2444 or S-2288. When plasminogen activator was present in the sample, the p-nitroanilide bound at the C-terminal of the tripep tide was released and the optical density at 405 nm increased [4,12). Measurements of the optical density at 405 nm were carried out with a 2-wavelength mi croplate photometer (Corona Electric, MTP-22, To kyo), calculated with a microcomputer (NEC, PC-9801, Tokyo) and recorded with a printer (Corona, MTP-12, Tokyo).…”