Fig. 5: Conserved F185 and Y217 residues contribute both to 15-PGDH enzymatic function and to 15-PGDH binding of inhibitors.
From: Small molecule inhibitors of 15-PGDH exploit a physiologic induced-fit closing system
a Shown is the melting temperature (Tm) of wild type and mutant 15-PGDH proteins (gray bar), along with increments of Tm acquired upon addition of NADH (orange bar), or upon addition of both NADH plus drug (blue bar). F185A and Y217A are individual point mutants and DM is the F185A + Y217A double mutant. b Michaelis–Menten enzyme kinetics for wild type and mutant 15-PGDH proteins in oxidizing PGE2. Wild-type PGDH has a Km of 2.2 µM and Hill coefficient nH = 1.0; the Y217A mutant has a Km of 11 µM and nH = 1.0; and F185A and the double mutant are both inactive. Data are presented as mean values ±SD (n = 3). c Percent inhibition (0–100%) of wild type and F217A mutant 15-PGDH enzyme activity versus concentration for (+)-SW209415 and SW222746, with a concentration in log scale. At a tested 15-PGDH protein concentration of 2 nM, IC50 values for (+)-SW209415 for wild type and Y217A are 0.43 and 0.86 nM, respectively, and IC50 values for SW222746 for wild type and Y217A are 1.2 and 8.5 nM, respectively.
