S-2222™ for Fxa

Product Overview:

S-2222™ is a synthetic chromogenic substrate for Factor Xa, and it is also highly sensitive to trypsin. It is intended for quantitative, kinetic determinations of Factor Xa activity. For general laboratory use only reagent for professional use only.

Principle and Application:

The substrate, N-Benzoyl-L-isoleucyl-L-glutamyl-glycyl-L-arginine-p-nitroaniline, is specifically cleaved by Factor Xa, releasing the chromogenic group p-Nitroaniline (pNA). The rate of pNA release is measured photometrically at 405 nm and is directly proportional to the enzymatic activity. This substrate is suitable for the determination of Factor X, Factor Xa, Factor Xa inhibitors, Heparin, and Factor VIII in plasma, as well as for measuring trypsin in duodenal fluid and the coagulating enzyme from horseshoe crab.

Product Composition and Specifications:

Each vial contains 25 mg of lyophilized chromogenic substrate S-2222™ with 120 mg of Mannitol as a bulking agent.

• Chemical Name: N-Benzoyl-L-isoleucyl-L-glutamyl-glycyl-L-arginine-p-nitroaniline hydrochloride and its methyl ester
• Formula: Bz-Ile-Glu-(γ-OR)-Gly-Arg-pNA · HCl (50% where R is H and 50% where R is CH₃)
• Molecular Weight: 734.3 (R = H) and 748.3 (R = CH₃)
• Molar Absorptivity (ε_316nm): 1.27 · 10⁴ mol^-1 · L · cm^-1
• Solubility: 6 mmol/L in H₂O; 2 mmol/L in Tris buffer (pH 8.3, I 0.25)

Performance Characteristics:

The substrate is highly sensitive to Factor Xa and trypsin. The substrate is also sensitive to subtilisin, acrosin and Factor XIIa but insensitive to most other enzymes tested, e.g. Factor IXa, kallikrein (glandular and plasma) and papain-like enzymes.

• Kinetic Data with Bovine Factor Xa:
  • K_m: 3 · 10^-4 mol/L
  • k_cat: 100 s^-1
  • (Conditions: 37°C, Tris buffer pH 8.3, I 0.25)
• Kinetic Data with Porcine Trypsin:
  • K_m: 2 · 10^-5 mol/L
  • k_cat: 280 s^-1
  • (Conditions: 37°C, Tris buffer pH 9.0, I 0.25)

Storage and Stability:

• Unopened (Lyophilized) Vial: Stable for more than 3 years when stored at 2-8°C. The substance is somewhat hygroscopic and should be stored dry.
• Reconstituted Solution: A 4 mmol/L solution in H₂O is stable for at least 6 months at 2-8°C. Avoid contamination by microorganisms, which may cause hydrolysis.

Disclaimer:

The information on this page is for informational purposes and serves as a general summary. It is imperative that all users read and strictly follow the Instructions for Use (IFU) document provided with the reagent or kit they are using. This online description must not be a substitute for the official product documentation.