Extended Data Fig. 8: S1P hydrolysis is sensitive to interprotomer coupling.
From: Structural basis for the catalytic mechanism of human lipid phosphate phosphatases
a, Some conserved residues in the C1, C2, and C3 loops participate in tetramerization and coordinating PAE molecules. In LPP1-A, the catalytic cavity is marked with a dotted circle, and the interfaces with LPP1-B and LPP1-D are indicated with black dotted lines. b, The chemical structures of LPA and S1P. The major differences are indicated with red dotted ellipses. c, The SEC profiles for the purification of the LPP1-WT&H223A chimera. Inset: Immunoblotting analysis demonstrates successful isolation of WT&H223A chimera. These experiments were conducted at least three times and the results shown here are the representative of those trials. d, Functional examination of the ability of the WT&H223A chimera to hydrolyze LPA, PA, and S1P. The WT&H223A chimera exhibits normal activities to hydrolyze LPA and PA but an obvious reduction in the dephosphorylation of S1P. These biochemical characterizations suggest that S1P hydrolysis is coupled between adjacent protomers, whereas LPA and PA hydrolysis are more independent for each protomer. WT+H223A, a mixture of WT and H223A enzymes after purification. In this experiment, 0.01 µg of enzymes was used to dephosphorylate LPA and PA at 37 °C for 10 min, whereas 0.03 µg of enzymes was employed to hydrolyze S1P at 37 °C for 20 min due to the relatively lower activity of the enzymes. Data are presented as the means ± s.d. of three independent experiments, each with two technical repeats (n=6).
