A Spectrophotometric Assay for the Determination of the Catalytic Efficiency of Plasminogen Activators Using a Slowly Hydrolyzed Plasmin Substrate

✍ Scribed by M.J.M. Castro; I.B. Kingston; S. Anderson

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 591 KB
• Volume: 226
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1995.1218

✦ Synopsis

A simple spectrophotometric assay for the determination of the catalytic efficiency and activity of plasminogen activators is presented. The assay system contains activator, plasminogen, and the chromogenic substrate (N)-benzoyl-L-arginine-p-nitroanilide (BAPA). Plasmin production is monitored continuously by the hydrolysis of BAPA under non-steady-state, first-order conditions with respect to plasminogen. Apparent catalytic efficiency constants are calculated from the values obtained for the apparent first-order rate constant of activation. The results obtained with the present method were compared with the catalytic efficiency determined through the measurement of (\boldsymbol{k}{\text {cat }}) and (K{m}), using a different system, under steady-state conditions. Tissue plasminogen activator in the absence and presence of fibrinogen and high-molecular-weight urokinase were used as model activators. Potential applications are discussed. (c 1995) Academic Press, Inc.