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Updated: Jun 8, 2026

Incorporating Target Protein Structure Flexibility and Dynamics in Computational Drug Discovery Using Ensemble-Based Docking Analysis
Published on: June 20, 2025
Structure-based optimization and biological evaluation of human 20α-hydroxysteroid dehydrogenase (AKR1C1) salicylic
Ossama El-Kabbani1, Peter J Scammells, Tom Day
1Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia. ossama.el-kabbani@monash.edu
Abstract:
The tertiary structure of the Leu308Val mutant of human 20α-hydroxysteroid dehydrogenase (AKR1C1) in complex with the inhibitor 3,5-dichlorosalicylic acid (DCL) has been determined. Structures and kinetic properties of the wild-type and mutant enzymes indicate that Leu308 is a selectivity determinant for inhibitor binding. The Leu308Val mutation resulted in 13-fold and 3-fold reductions in the inhibitory potencies of DCL and 3-bromo-5-phenylsalicylic acid (BPSA), respectively. The replacement of Leu308 with an alanine resulted in 473-fold and 27-fold reductions in the potencies for DCL and BPSA, respectively. In our attempts to optimize inhibitor potency and selectivity we synthesized 5-substituted 3-chlorosalicylic acid derivatives, of which the most potent compound, 3-chloro-5-phenylsalicylic acid (K(i) = 0.86 nM), was 24-fold more selective for AKR1C1 relative to the structurally similar 3α-hydroxysteroid dehydrogenase (AKR1C2). Furthermore, the compound inhibited the metabolism of progesterone in AKR1C1-overexpressed cells with an IC(50) value equal to 100 nM.
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