Phosphatidylserine modulates calf intestine alkaline phosphatase activity towards low and high molecular weight substrate.

Pretreatment of calf intestine alkaline phosphatase with phosphatidylserine resulted in an inhibition of the phosphatase activity towards low - (p-nitrophenylphosphate) and high (phosphohistone) molecular weight substrate. Phosphatidylcholine, irrespectively of the substrate used did not cause enzyme modulation. 12-O-tetradecanoylphorbol-13-acetate, 1,2-diolein as well certain retinoids, known to effect phosphatidylserine-sensitive enzyme systems (Castagna, M. et al. 1982, J. Biol. Chem. 257, 7847-7851; Gmeiner, B. 1986, Biochim. Biophys. Acta 856, 392-394) had no influence on the modulated phosphatase. The lipid interacting drug trifluoperazine inhibited the enzyme activity towards phosphohistone, but not towards p-nitrophenylphosphate as a substrate. The results indicate that acidic phospholipid may play a role in activity modulation of calf intestine membranous alkaline phosphatase activity.