DiaPharma Group, Inc.

For research use only

S-2403 is a chromogenic substrate for plasmin and streptokinase-activated plasminogen.

Reagent -- Composition, Packaging, Storage and Stability

Each vial contains the chromogenic substrate S-2403 25 mg and mannitol 60 mg as a bulking agent. Stability: Substance: Stable until expiry date if stored at 2-8°C. Avoid exposure to light. The substance is hygroscopic and should be stored dry. Solution: 7.5 mmol/L in H2O is stable for at least 6 months at 2 to 8°C.

** Also available in bulk sizes (500+ mg) as a special order.

Chemistry

Chemical name: L-Pyroglutamyl-L-Phenylalanyl-L-Lysine-p-Nitroaniline hydrochloride.

S-2403 structure

Mol. wt: 561.0

e316 nm: 1.27 . 104 mol-1 . L . cm-1

Solubility: >40 mmol/L in H2O

Suitable stock solution: 3-8 mmol/L in H2O.

Principle

The method for the determination of activity is based on the difference in absorbance (optical density) between the pNA formed and the original substrate.

The rate of pNA formation, i.e. the increase in absorbance per second at 405 nm, is proportional to the enzymatic activity and is conveniently determined with a photometer

Kinetic Data

Plasmin (human): Km=2.9 · 10-4 mol/L, kcat=92 s-1.

PlasminogenSK: Km=3.0 · 10-4 mol/L, kcat=43 s-1.

Determined at 37°C in Tris buffer pH 7.4, I 0.15.

Selectivity

The substrate is insensitive to plasma-kallikrein, thrombin and FXa.

Standardization

An activity of DA/min = 0.30 (37°C) is obtained by using a substrate concentration of 0.4 mmol/L and:

1. 7.8 · 10-9 mol/L of human plasmin from Chromogenix.
2. 1.2 · 10-8 mol/L of SK-activated human plasminogen from Chromogenix.