Sterol 14-alpha-demethylase (fungal) (CYP51 (ERG11))

Sterol 14-alpha-demethylase (fungal) is a membrane-bound enzyme belonging to the cytochrome P450 superfamily, specifically designated as CYP51 or ERG11 in fungi[2][6][7]. This enzyme catalyzes the oxidative removal of the 14-alpha-methyl group from lanosterol and related sterols, a critical step in the biosynthesis of ergosterol—the major sterol component of fungal cell membranes[1][2][3]. The absence or inhibition of this activity disrupts ergosterol synthesis, alters membrane fluidity and integrity, and impairs fungal growth and viability[1][2]. This enzyme is an established and clinically critical therapeutic target for azole antifungal drugs, which are among the most widely used treatments for fungal infections in humans, animals, and plants[2][6][7]. Fungal resistance to azoles frequently arises via mutations or overexpression of the CYP51/ERG11 gene, highlighting its centrality in both pathogenicity and antifungal pharmacology[2][6][7].

Other names

Lanosterol 14-alpha demethylaseSterol 14α-demethylaseERG11 (gene encoding the enzyme in *Saccharomyces cerevisiae*)CYP51 (systematic name for the cytochrome P450 family 51 member)

Azoles: Bind to the heme iron in the active site of CYP51, inhibiting demethylation of lanosterol, which disrupts ergosterol synthesis; impairs membrane function and integrity leading to fungal cell death[2][6]. Other inhibitors (e.g. cinnamaldehyde): Downregulate gene expression or reduce enzyme activity[1].