Figure 6. Molecular pathways of 18S-RvE1 actions: ligand-receptor interaction and metabolic inactivation.

(A) ChemR23 activation. Increasing doses of RvE1 (diamonds) or 18S-RvE1 (squares) were incubated with the ChemR23-overexpressing reporter system, followed by β-gal substrate incubation. Luminescence was measured to obtain the RvE1 EC₅₀, 1.37 × 10^–10 M, and 18S-RvE1 EC₅₀, 6.33 × 10^–12 M, from fitted dose-response curves. (B) BLT1 antagonism. BLT1-overexpressing cells were incubated with different concentrations of 18S-RvE1 or RvE1, followed by 30 nM LTB₄, and further incubated for 30 minutes. Results are mean ± SEM; n ≥ 3. P < 0.05, RvE1 versus 18S-RvE1. (C) Comparison between RvE1 and 18S-RvE1 by 15-PGDH–mediated oxidation (diamonds: RvE1, squares: 18S-RvE1) addressed in the presence of NAD⁺ as a cofactor. NADH was monitored as a readout of dehydrogenation. Results shown are representative of n = 3 with similar trends.