Protease Inhibitors Extracted from Caesalpinia echinata Lam. Affect Kinin Release during Lung Inflammation

Table 1

Specificities of rCeEI and CeKI on enzymes.

	(nM)
	rCeEI	CeKI
Neutrophil elastase	0.67 ± 0.05	n.i.
Neutrophil cathepsin G	6.54 ± 0.11	2100 ± 630
Neutrophil proteinase 3	3700 ± 67	2700 ± 205
Plasma kallikrein	1.00 ± 0.08	3.1 ± 0.1
Tissue kallikrein 1	n.i.	n.i.
Angiotensin-converting enzyme	n.i.	n.i.

“n.i.”: no detectable inhibition.
Cruz-Silva et al., 2004.
NE (1.0 nM), Cat G (17 nM), PR3 (0.20 µM), plasma kallikrein (4.0 nM), KLK1 (18 nM), and ACE (20 nM) activities were determined by observing the hydrolysis of the appropriate substrates, namely, MeO-Suc-A-A-P-V-pNA (0.20 mM), Suc-A-A-P-F-pNA (0.30 mM), MeO-Suc-A-A-P-V-pNA (0.20 mM), H-D-P-F-R-pNA (0.30 mM), H-D-P-F-R-pNA (0.30 mM), and Abz-F-R-K(Dnp)-P-OH (10 μM), respectively. The enzymes were preincubated in appropriate buffer for 10 min at 37°C with increasing amounts of rCeEI or CeKI. The -nitroaniline release was followed at 405 nm or the fluorescence was measured at = 320 nm and = 420 nm and values were calculated.