H-D-Phe-Pip-Arg-pNA

H-D-Phe-Pip-Arg-pNA (S-2238) is a specific chromogenic peptide substrate for thrombin (Thrombin). The amide bond of H-D-Phe-Pip-Arg-pNA is rapidly hydrolyzed by thrombin, producing a characteristic yellow absorbance at 405 nm, and the change in absorbance is proportional to thrombin activity. H-D-Phe-Pip-Arg-pNA can be used in biochemical detection-related studies^[1][2]. In Vitro:H-D-Phe-Pip-Arg-pNA (S-2238) (compound 3) enables a sensitive, accurate thrombin-based chromogenic assay for heparin in human plasma, with a minimum detectable heparin concentration of 0.005 U/mL in normal plasma; the performance of this assay at low heparin concentrations is improved when purified human antithrombin III is used^[1].
H-D-Phe-Pip-Arg-pNA is the most reactive substrate for plasmin F-III-2 and F-III-1 purified from Lumbricus rubellus^[2].
H-D-Phe-Pip-Arg-pNA can be acted upon by plasmin purified from Lumbricus rubellus; these plasmins retain full amidolytic activity towards this substrate after incubation at 37°C and pH 1-11 for 30 min; the amidolytic activity of plasmin towards this substrate is strongly inhibited by DFP, SBTI and aprotinin^[2].