Table 2. Inhibition constant (K _i values) of elafin (Zani et al., 2004 ▶) and 50% inhibitory concentrations (IC50) of 1/2SLPI and against some serine proteases (Masuda et al., 1994 ▶).

	K i (M) of elafin	IC50 of 1/2SLPI
	57 amino acids A1G57	49 amino acids R58A107
	42% identity with 1/2SLPI	C-terminal domain of SLPI
H. neutrophil elastase	1 1010	1.3 108
P. pancreatic elastase	1 109	3.3 105
H. cathepsin G		8.0 109
B. pancreatic chymotrypsin		8.0 109
B. pancreas trypsin		2.0 106