[A photometric method of determining the activity of antithrombin III using a peptide coumarylamide substrate].

Toz-Gly-Pro-Arg-4-methylcoumaryl-7-amide is recommended for antithrombin-III (AT-III) photometry as a substrate. This substrate is cleaved by thrombin at 366 nm. AT-III photometry with this substrate is in accord with the requirements to methods used in clinical laboratory diagnosis, and the results of such measurement are in good correlation with the data of AT-III analysis with Chromozym-TH substrate. Use of photometry with methylcoumaryl substrates for measuring protease activities is more available than the traditional fluorometry.