This enzyme belongs to the family of
oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derive from O miscellaneous. The
systematic name of this enzyme class is cholesterol, hydrogen-donor:oxygen oxidoreductase (25-hydroxylating). This enzyme is also called cholesterol 25-monooxygenase.
Transcripts for this enzyme have been identified in macrophages from the testis.
CH25H is an
interferon-stimulated gene, and its primary product 25HC may have broad-spectrum
antiviral activity, demonstrated in mice against
HIV,
ebola,
Nipah virus,
Rift Valley Fever virus, and SARS-CoV-2. Specifically, 25HC blocks membrane fusion between the cell and virus, and may "implicate membrane-modifying oxysterols as potential antiviral therapeutics.” Recently, upregulation of CH25H has been shown to play a role in effectively restricting infection of lung epithelial cells with SARS-Cov-2 through its enzymatic product, 25HC, which depletes accessible membrane cholesterol so that the virus is unable to achieve fusion with the cell membrane necessary for entry and infection.[1]
It has been proposed, based on experimental research in both mice and human cell culture, that 25HC is a potent
senolytic. Further research needs to elaborate on this research and reveal its true significance to aging.[2]
Chen JJ, Lukyanenko Y, Hutson JC (May 2002). "25-hydroxycholesterol is produced by testicular macrophages during the early postnatal period and influences differentiation of Leydig cells in vitro". Biology of Reproduction. 66 (5): 1336–41.
doi:
10.1095/biolreprod66.5.1336.
PMID11967195.
S2CID22637279.
Fox BG, Shanklin J, Ai J, Loehr TM, Sanders-Loehr J (November 1994). "Resonance Raman evidence for an Fe-O-Fe center in stearoyl-ACP desaturase. Primary sequence identity with other diiron-oxo proteins". Biochemistry. 33 (43): 12776–86.
doi:
10.1021/bi00209a008.
PMID7947683.