D-Val-Gly-Arg-pNA

D-Val-Gly-Arg-p-nitroaniline (D-VGR-pNA) ​ is a synthetic chromogenic peptide substrate specifically designed for assessing the enzymatic activity of tissue plasminogen activator (tPA), including its isoforms tPA I and tPA II. Upon cleavage by tPA, the release of p-nitroaniline (pNA) generates a measurable colorimetric signal, enabling precise quantification of amidolytic activity. This substrate is widely utilized in biochemical assays to study tPA’s role in fibrinolysis and to evaluate its enzymatic kinetics in both research and diagnostic applications.