TABLE 2.

rIrCD1 sensitivity to specific protease inhibitors

Recombinant IrCD1 was preincubated with the given inhibitor, and the remaining activity was measured in a kinetic assay with the FRET substrate Abz-KPAEFnFRL. Mean values ± S.D. are expressed as the percentage inhibition compared with the uninhibited control.

Inhibitor	Specificity/target protease	Concentration	Inhibition
			%
Pefabloc	Serine proteases (37)	1 mm	3 ± 1
E-64	Cysteine proteases (39)	10 μm	4 ± 2
Leupeptin	Serine and cysteine proteases (38)	10 μm	9 ± 4
EDTA	Metalloproteases (40)	10 μm	2 ± 1
Lopinavir	Aspartic proteases of retropepsin family (36)	10 μm	61 ± 5
Pepstatin	Aspartic proteases of pepsin and retropepsin families (34)	1 μm	99 ± 4
Potato cathepsin D inhibitor (PDI)	Aspartic proteases of cathepsin D type (35)	1 μm	100 ± 2