Table 1. Functional parameters of PMM1, PMM2 and QDK-PMM1.

Enzymatic activities were measured at the specified conditions and results were expressed as % of the PMM activity. K_M and K_a were determined from a Michaelis-Menten plot.

parameter	Experimental conditions	PMM2	PMM1	QDK-PMM1
PMM activity	200μM Man-1-Psaturating Man-1,6-P2	100 ± 9	100 ± 10	100 ± 8
PGM activity	600μM Glc-1-P saturating Glc-1,6-P2	5.8 ± 0.6	33.5 ± 3.5	41.7 ± 3.8
phosphatase activity	145μM Glc-1,6-P2	0.013 ± 0.002	2.35 ± 0.21	4.59 ± 0.45
phosphatase activity	80μM Man-1,6-P2	0.015 ± 0.002	2.03 ± 0.65	1.50 ± 0.31
phosphatase activity	145μM Glc-1,6-P2 170μM IMP	0.014 ± 0.004	40.6 ± 15.9	4.20 ± 1.63
phosphatase activity	80μM Man-1,6-P2 170μM IMP	0.016 ± 0.003	27.2 ± 5.0	1.52 ± 0.33
KM Man-1-P, μM	10μM Man-1,6-P2 variable Man-1-P	23.7 ± 4.5 *	6.5 ± 1.3	1.6 ± 0.4
KM Glc-1-P, μM	27μM Glc-1,6-P2 variable Glc-1-P	8.2 ± 0.7	7.3 ± 1.7	3.5 ± 1.3
Ka Man-1,6-P2, μM	200μM Man-1-P variable Man-1,6-P2	5.4 ± 0.6	17.0 ± 2.3	8.8 ± 1.2
Ka Glc-1,6-P2, μM	600μM Glc-1-P variable Glc-1,6-P2	9.0 ± 1.6	81.6 ± 12.4	23.2 ± 4.9
KM Glc-1,6-P2, μM	variable Glc-1,6-P2	nd	3.9 ± 0.3	nd
Ka IMP, μM	150μM Glc-1,6-P2 variable IMP	nd	8.6 ± 2.3	nd

* 3μM Man-1,6-P₂

nd, not determined