DiaPharma Group, Inc.

For research use only

S-2772 is a chromogenic substrate selective for coagulation factor Xa.

Reagent -- Composition, Packaging, Storage and Stability

The vial contains the chromogenic substrate S-2772 26 mg and mannitol 40 mg as a bulking agent.

Stability: Substance stable until the expiry date if stored at 2-8°C. Avoid exposure to light. The substance is hygroscopic and should be stored dry.

Solution: 2 mmol/l in sterile water is stable for at least 6 month 2-8°C.

Working solutions in buffer with pH above 6 possess a considerably reduced stability. Contamination by microorganisms may cause hydrolysis of the substrate.

Suitable stock solution: Dissolve the content of the vial in sterile water to a concentration of 1-4 mmol/l. This stock solution is then further diluted in the chosen buffer prior to use.

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

Properties

Chemical name: N-a-Acetyl-D-arginyl-L-glycyl-L-arginine-p-nitroaniline dihydrochloride

Formula: N-a-Ac-D-Arg-Gly-Arg-pNA·2HCl

S-2772 structure

MW: 622.5

e316 nm: 12 400 mol-1 · L · cm-1

Solubility: > 40 mmol/l in H2O

Priniciple

	Enzyme
Substrate		Peptide + pNA

The reaction between the enzyme and the chromogenic substrate results in the cleavage of pNA from the substrate. The rate of pNA formation, as measured by an increase in the absorbance at 405 nm, is proportional to the enzyme activity.

Kinetic Data

Buffer: Tris-HCl (50 mM), pH 8.3, NaCl (130mM)
Factor Xa bovine(B) Km 0.70 mM kcat 100 s-1
Factor Xa human(H) Km 1.5 mM kcat 120 s-1
FxDA/min = 0.32 at a substrate concentration of 2xKm.

Selectivity

Relative reactivity of S-2772 with various enzymes at a substrate concentration of 2xKm: factor Xa(B)100%, thrombin(B) 1%, factor XIa(H)1%, activated protein C (H) 2%, plasmin(H) 1%, t-PA(H) 4%, plasma kallikrein (H) 4%, C1s(H) 5%.