Crystal structures of human 17β‐hydroxysteroid dehydrogenase type 1 complexed with estrone and NADP⁺ reveal the mechanism of substrate inhibition

Abstract

Human 17β‐hydroxysteroid dehydrogenase type 1 (17β‐HSD1) catalyses the last step in estrogen activation and is thus involved in estrogen‐dependent diseases (EDDs). Unlike other 17β‐HSD members, 17β‐HSD1 undergoes a significant substrate‐induced inhibition that we have previously reported. Here we solved the binary and ternary crystal structures of 17β‐HSD1 in complex with estrone (E1) and cofactor analog NADP+, demonstrating critical enzyme‐substrate‐cofactor interactions. These complexes revealed a reversely bound E1 in 17β‐HSD1 that provides the basis of the substrate inhibition, never demonstrated in estradiol complexes. Structural analysis showed that His221 is the key residue responsible for the reorganization and stabilization of the reversely bound E1, leading to the formation of a dead‐end complex, which exists widely in NADP(H)‐preferred enzymes for the regulation of their enzymatic activity. Further, a new inhibitor is proposed that may inhibit 17β‐HSD1 through the formation of a dead‐end complex. This finding indicates a simple mechanism of enzyme regulation in the physiological background and introduces a pioneer inhibitor of 17β‐HSD1 based on the dead‐end inhibition model for efficiently targeting EDDs. Databases Coordinates and structure factors of 17β‐HSD1‐E1 and 17β‐HSD1‐E1‐NADP+ have been deposited in the Protein Data Bank with accession code and respectively. Enzymes 17β‐hydroxysteroid dehydrogenase type 1 (17β‐HSD1) EC 1.1.1.62.

Molecular Docking Studies of Estrone-Coumarin Derivatives as Aromatase and 17<i>β</i>-HSD1 Inhibitors Related to Hormone Receptor Positive (HR+) Breast Cancer

“…This inverse orientation causes inhibition of the enzyme, forming a dead-end complex that cannot be catalyzed. This type of inhibition, also reported in other enzymes, has been related with high concentrations of substrate [41] [42] [43] [44] [45].…”

Phytoconstituents of Withania somnifera unveiled Ashwagandhanolide as a potential drug targeting breast cancer: Investigations through computational, molecular docking and conceptual DFT studies

“…Human 17β-HSD1 is a human steroid-converting enzyme that catalyzes the final steps in activating estrogens (especially estradiol), which promote the proliferation of hormone-dependent diseases like breast cancer [ 58 , 59 ]. Its expression positively correlates with the activation of estrone, estradiol levels, and breast cancer cell proliferation.…”

“…The expression and activity of 17β-HSD1 are much higher in breast cancer than in normal breast tissue, and this increased expression has been postulated as a possible explanation for the elevated estradiol content in breast cancer [ 58 ]. It is also known to be involved in the reduction of dehydroepiandrosterone (DHEA) into 5-androstene-3β,17β-diol (A-diol) and dihydrotestosterone (DHT) into 5α-androstane-3β,17β-diol (3β-diol) [ 59 ]. A-diol has been reported as the major estrogen found after menopause, whereas 3β-diol was capable of inducing the activation and proliferation of ERα.…”

Chemical Synthesis and Biological Evaluation of 3-Substituted Estrone/Estradiol Derivatives as 17β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors Acting via a Reverse Orientation of the Natural Substrate Estrone

“…Different strategies have therefore been used so far to develop 17β-HSD1 inhibitors [ 14 , 15 , 16 , 17 , 18 ]. More recently, and by resolving the binary and ternary crystal structures of 17β-HSD1 in complex with estrone (E1) as well as with the cofactor NADP + and E1 [ 19 ], some critical enzyme-substrate-cofactor interactions have been observed. Notably, the structural analysis of these two complexes showed interesting interactions between the His-221 imidazole residue and the natural substrate E1 positioned in a reversed side, leading to the formation of a dead-end complex ( Figure 2 A) [ 19 ], as opposed to the classic complex between 17β-HSD1 and E1 positioned in normal side ( Figure 2 B), which allows the formation of E2 [ 20 ].…”

“…More recently, and by resolving the binary and ternary crystal structures of 17β-HSD1 in complex with estrone (E1) as well as with the cofactor NADP + and E1 [ 19 ], some critical enzyme-substrate-cofactor interactions have been observed. Notably, the structural analysis of these two complexes showed interesting interactions between the His-221 imidazole residue and the natural substrate E1 positioned in a reversed side, leading to the formation of a dead-end complex ( Figure 2 A) [ 19 ], as opposed to the classic complex between 17β-HSD1 and E1 positioned in normal side ( Figure 2 B), which allows the formation of E2 [ 20 ]. From modeling work, the authors proposed that compound 5 could inhibit 17β-HSD1 through the formation of a dead-end-type complex ( Figure 2 C) [ 19 ].…”