Metabolism of Lumisterol2 by CYP27A1

Dongxian Wu; Gareth Nealon; Yuchen Liu; Tae-Kang Kim; Andrzej T Slominski; Robert C Tuckey

doi:10.1016/j.jsbmb.2023.106370

Metabolism of Lumisterol₂ by CYP27A1

J Steroid Biochem Mol Biol. 2023 Oct:233:106370. doi: 10.1016/j.jsbmb.2023.106370. Epub 2023 Jul 25.

Authors

Dongxian Wu¹, Gareth Nealon², Yuchen Liu¹, Tae-Kang Kim³, Andrzej T Slominski⁴, Robert C Tuckey⁵

Affiliations

¹ School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
² School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia; Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia.
³ Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA.
⁴ Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, USA; VA Medical Center, Birmingham, AL, USA.
⁵ School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia. Electronic address: robert.tuckey@uwa.edu.au.

PMID: 37499840
DOI: 10.1016/j.jsbmb.2023.106370

Abstract

Lumisterol₂ (L2) is a photoproduct of UVB action on the fungal membrane sterol, ergosterol. Like vitamin D₂, it is present in edible mushrooms, especially after UV irradiation. Lumisterol₃ is similarly produced in human skin from 7-dehydrocholesterol by UVB and can be converted to hydroxy-metabolites by CYP27A1 and CYP11A1. These products are biologically active on human cells with actions that include photoprotection and inhibition of proliferation. The aim of this study was to test the ability of CYP11A1 and CYP27A1 to metabolise L2. Purified CYP27A1 was found to efficiently metabolise L2 to three major products and several minor products, whilst CYP11A1 did not act appreciably on L2. The three major products of CYP27A1 action on L2 were identified by mass spectrometry and NMR as 24-hydroxyL2, 27-hydroxyL2 and 28-hydroxyL2. Minor products included two dihydroxy L2 species, one which was identified as 24,27(OH)₂L2, and another metabolite with one oxo and one hydroxyl group added. A comparison on the kinetics of the metabolism of L2 by CYP27A1 with that of the structurally similar compounds, L3 and ergosterol, was carried out with substrates incorporated into phospholipid vesicles. CYP27A1 displayed a 12-fold lower K_m with L2 as substrate compared to L3 and a 5-fold lower turnover number (k_cat), resulting in a 2.2 fold higher catalytic efficiency (k_cat/K_m) for L2 metabolism. L2 was a much better substrate for CYP27A1 than its precursor, ergosterol, with a catalytic efficiency 18-fold higher. The major CYP27A1-derived hydroxy-L2 products, 24-hydroxyL2, 27-hydroxyL2 and 28-hydroxyL2, inhibited the proliferation of melanoma and epidermoid cancer cell lines. In conclusion, this study shows that L2 is not metabolized appreciably by CYP11A1, but it is a good substrate for CYP27A1 which hydroxylates its side chain to produce 3 major products that display anti-proliferative activity on skin-cancer cell lines.

Keywords: CYP11A1; CYP27A1; Hydroxylation; Lumisterol(2); Vitamin D.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Cholestanetriol 26-Monooxygenase / metabolism
Cholesterol Side-Chain Cleavage Enzyme* / metabolism
Ergocalciferols
Ergosterol* / metabolism
Humans
Hydroxylation
Mass Spectrometry

Substances

Ergosterol
Cholesterol Side-Chain Cleavage Enzyme
Ergocalciferols
CYP27A1 protein, human
Cholestanetriol 26-Monooxygenase

Abstract

Publication types

MeSH terms

Substances

Grants and funding