. Author manuscript; available in PMC: 2008 Sep 23.

Published in final edited form as: J Biol Chem. 1999 Apr 16;274(16):11139–11149. doi: 10.1074/jbc.274.16.11139

Table II. Kinetic analysis of the partially purified 4′-phosphatase and phosphotransferase.

The kinetic constants for the 4′-phosphatase and the phosphotransferase reactions were determined from assays at varying concentrations of Kdo₂-[4′-³²P]lipid IV_A, Kdo-[4′-³²P]lipid IV_A, or [4′-³²P]lipid IV_A in the presence or absence of PtdIns (1 mg/ml). The apparent K_m and V_max were then estimated from double reciprocal plots. The V_maxof the phosphotransferase reaction is higher than that of the 4′-phosphatase with each substrate.

Donor substrate	Acceptor substrate	Apparent K_m	V_max
		μM	nmol/min/mg
Kdo₂-lipid IV_A	Water	30.4	73.9
	PtdIns	32.1	170.0
Kdo-lipid IV_A	Water	40.5	55.6
	PtdIns	38.2	122.3
Lipid IV_A	Water	144.6	30.0
	PtdIns	150.4	57.0