TABLE 2.

Inhibitor sensitivity and metal ion dependence of Pz peptidases A and B

Agenta	Concn (mM)	Remaining activity (%)
		Pz peptidase A	Pz peptidase B
Control		100	100
EDTA	2	0	0
1,10-Phenanthroline	2	0	0
PMSF	2	106	97
DFP	2	122	81
N-Ethylmaleimide	2	33	69
Dithiothreitolb	0.1	88	85
	1	68	13
CaCl2	2	86	119
MgCl2	2	81	108
FeCl2	2	0	8
ZnCl2	2	0	0
NiCl2	2	0	0
CuCl2	2	0	0
CoCl2	0.01	148	336
	2	8	12
MnCl2	0.5	217	321
	2	87	84

^aPMSF, phenylmethylsulfonyl fluoride; DFP, diisopropyl fluorophosphate.

^bDithiothreitol was preincubated with the enzymes overnight in the concentration indicated, and due to significant noise by dithiothreitol, the enzyme activity was assayed with the sample diluted 200-fold.