D-Val-Leu-Lys-pNA dihydrochloride  (Synonyms: D-Val-Leu-Lys-p-itoailide dihydrochloride; D-VLK-pNA dihydrochloride; S 2251 dihydrochloride)

D-Val-Leu-Lys-pNA (D-Val-Leu-Lys-p-nitroanilide) dihydrochloride is a chromogenic peptide substrate that serves as a characteristic substrate for plasmin and plasminogen. D-Val-Leu-Lys-pNA dihydrochloride acts as a sensitive substrate for the DFE27 serine protease derived from Bacillus subtilis DC27. Catalyzed by plasmin, D-Val-Leu-Lys-pNA dihydrochloride binds and hydrolyzes to release p-nitroaniline (pNA), which can be detected colorimetrically at 405 nm as a measure of fibrinolytic activity^[1][2].

D-Val-Leu-Lys-pNA dihydrochloride (1 mM; 30 min at 37°C) was the substrate against which purified DFE27 serine protease from Bacillus subtilis DC27 exhibits the highest amidolytic activity, with a hydrolysis rate of 225.291 mmol·min⁻¹·mL^−1[1].
D-Val-Leu-Lys-pNA dihydrochloride (0.16 mM) is hydrolyzed by Lys-gingipain from Porphyromonas gingivalis (strain H66) with a K_m of 0.2 mM, V_max of 133 mmol/min, and V_max/K_m ratio of 665^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

551.51

C₂₃H₄₀Cl₂N₆O₅

62354-43-2

Solid

White to off-white

{d-Val}-Leu-Lys-{pNA}

{d-Val}-LK-{pNA}

Room temperature in continental US; may vary elsewhere.

Stored under nitrogen, away from moisture

*In solvent : -80°C, 6 months; -20°C, 1 month (stored under nitrogen, away from moisture)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (stored under nitrogen, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Hu Y, et al. Purification and characterization of a novel, highly potent fibrinolytic enzyme from Bacillus subtilis DC27 screened from Douchi, a traditional Chinese fermented soybean food. Sci Rep. 2019;9(1):9235. Published 2019 Jun 25.

  [2]. Pike R, et al. Lysine- and arginine-specific proteinases from Porphyromonas gingivalis. Isolation, characterization, and evidence for the existence of complexes with hemagglutinins. J Biol Chem. 1994 Jan 7;269(1):406-11.