Table 2. K_i and cLogP Values for SphK2-Selective Inhibitors^a.

^aInhibitory constants for recombinant enzymes were obtained by kinetic analysis of S1P production using variable concentration of sphingosine and a fixed concentration of ATP in the presence or absence of compounds as described previously.³⁰ Selectivity for each compound was determined by dividing the K_M for SphK2 by the K_M for SphK1. hSphK2 selectivity for each compound was determined by dividing K_i for hSphK1 by the K_i for hSphK2.

^bK_i for mouse SphK2 is 110 ± 13 nM and mouse SphK1 is >10 000 nM.