Table 2. Catalytic activity of PGP from T. brucei brucei.

The PGP activity was assayed in 50 mM Tris/HCl/1 mM EDTA/1 mM TCEP (pH 7.4). Values represent the means±S.D. (n=3).

	Native PGP			Recombinant PGP
Substrate*	Km (μM)	kcat (s−1)	kcat/Km (s−1·μM−1)	Km (μM)	kcat (s−1)	kcat/Km (s−1·μM−1)
Glp-AMC	18±6	58±12	3.2	28±6	47±9	1.7
Glp-pNA	28±9	52±7	1.9	44±8	64±8	1.5
Glu-AMC	n.h.	n.h.	n.h.	n.h.	n.h.	n.h.
Glu-pNA	n.h.	n.h.	n.h.	n.h.	n.h.	n.h.
Asp-AMC	n.h.	n.h.	n.h.	n.h.	n.h.	n.h.
Pro-AMC	n.h.	n.h.	n.h.	n.h.	n.h.	n.h.
TRH†	41±18	20±9	0.5	32±12	22±11	0.7
GnRH†	79±31	9±4	0.1	89±26	12±6	0.1

* No degradation of any substrate was observed by recombinant catalytically inactive (C167A) PGP. n.h., no hydrolysis detected.

† TRH and GnRH were hydrolysed exclusively at the Glp↓Xaa bond.