1α,25(OH)2-3-epi-vitamin D3, a Natural Physiological Metabolite of Vitamin D3: Its Synthesis, Biological Activity and Crystal Structure with Its Receptor
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Background: The 1α,25-dihydroxy-3-epi-vitamin-D3 (1α,25(OH)2-3-epi-D3), a natural metabolite of the seco-steroid vitamin D3, exerts its biological activity through binding to its cognate vitamin D nuclear receptor (VDR), a ligand dependent transcription regulator. In vivo action of 1α,25(OH)2-3-epi-D3 is tissue-specific and exhibits lowest calcemic effect compared to that induced by 1α,25(OH)2D3. To further unveil the structural mechanism and structure-activity relationships of 1α,25(OH)2-3-epi-D3 and its receptor complex, we characterized some of its in vitro biological properties and solved its crystal structure complexed with human VDR ligand-binding domain (LBD).
Methodology/principal Findings: In the present study, we report the more effective synthesis with fewer steps that provides higher yield of the 3-epimer of the 1α,25(OH)2D3. We solved the crystal structure of its complex with the human VDR-LBD and found that this natural metabolite displays specific adaptation of the ligand-binding pocket, as the 3-epimer maintains the number of hydrogen bonds by an alternative water-mediated interaction to compensate the abolished interaction with Ser278. In addition, the biological activity of the 1α,25(OH)2-3-epi-D3 in primary human keratinocytes and biochemical properties are comparable to 1α,25(OH)2D3.
Conclusions/significance: The physiological role of this pathway as the specific biological action of the 3-epimer remains unclear. However, its high metabolic stability together with its significant biologic activity makes this natural metabolite an interesting ligand for clinical applications. Our new findings contribute to a better understanding at molecular level how natural metabolites of 1α,25(OH)2D3 lead to significant activity in biological systems and we conclude that the C3-epimerization pathway produces an active metabolite with similar biochemical and biological properties to those of the 1α,25(OH)2D3.
Sabit H, Abdel-Ghany S, Abdallah M, Abul-Maaty O, Khoder A, Shoman N Inflammopharmacology. 2024; 32(6):3631-3652.
PMID: 39406981 PMC: 11550250. DOI: 10.1007/s10787-024-01578-w.
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Peluso-Iltis C, Pierrat N, Rovito D, Osz J, Sawada D, Kittaka A Biomolecules. 2024; 14(5).
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Okafor P, Homwong N Animals (Basel). 2024; 14(3).
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Kimsa-Furdzik M, Bednarek A, Hibner G, Czajka-Francuz P, Cison-Jurek S, Karawasiecka D Metabolites. 2023; 13(9).
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Maloney S Biomedicines. 2023; 11(2).
PMID: 36830861 PMC: 9953299. DOI: 10.3390/biomedicines11020324.