D-Val-Leu-Lys-pNA acetate (S-2251 acetate) is a chromogenic peptide substrate that serves as a characteristic substrate for plasmin and plasminogen. D-Val-Leu-Lys-pNA acetate acts as a sensitive substrate for the DFE27 serine protease derived from Bacillus subtilis DC27. Catalyzed by plasmin, D-Val-Leu-Lys-pNA acetate binds and hydrolyzes to release p-nitroaniline (pNA), which can be detected colorimetrically at 405 nm as a measure of fibrinolytic activity [1] [2].
In Vitro, D-Val-Leu-Lys-pNA (1 mM; 30 min at 37°C) acetate 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 (0.16 mM) acetate is hydrolyzed by Lys-gingipain from Porphyromonas gingivalis (strain H66) with a Km of 0.2 mM, Vmax of 133 mmol/min, and Vmax/Km ratio of 665[2].
References:
[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.
In Vitro, D-Val-Leu-Lys-pNA (1 mM; 30 min at 37°C) acetate 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 (0.16 mM) acetate is hydrolyzed by Lys-gingipain from Porphyromonas gingivalis (strain H66) with a Km of 0.2 mM, Vmax of 133 mmol/min, and Vmax/Km ratio of 665[2].
References:
[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.