Table 2. UppP activity of H. pylori PAP2 enzymes.

	UppP specific activity (nmol/min/mg)
pH	LpxE	HP0350	HP0851 (HupA)	LpxF
3	10	ND	131	30.8
4	13.8	ND	1227	97.2
5	21.3	ND	6039	130.3
6	291.3	ND	4616	97.5
7	671.3	ND	3755	91.8
7	735	ND	4157	84.8
7.4	900	ND	3493	71.5
8	492.5	ND	2528	48.8
9	285	ND	1180	28.7
9	76.3	ND	974	20.5
10	0	ND	159	9
11	8.8	ND	19	4.2

The enzymatic activity was measured in the presence of 50 μM of [¹⁴C]C₅₅-PP substrate and an appropriate amount of enzyme to obtain less than 30% of hydrolysis. Buffering of the reaction mixture was obtained with sodium acetate (pH 3–7), Tris-HCl (pH 7–9) or sodium carbonate (pH 9–11). The C₅₅-P product and the substrate were separated by TLC and further quantified by radioactivity counting. Values represent the mean of at least three individual experiments (the S.D. being within 15% of the presented values). ND, no detectable activity.