Lanosterol 14-alpha demethylase (Cryptococcus spp.) (CYP51)

Lanosterol 14-alpha demethylase, commonly known as CYP51 or Erg11, is a vital enzyme in the ergosterol biosynthesis pathway of Cryptococcus species, including Cryptococcus neoformans and Cryptococcus gattii (UniProt: P0C0L4). Ergosterol is a fundamental component of the fungal cell membrane, essential for maintaining structural integrity, fluidity, and the function of membrane-bound enzymes. CYP51 catalyzes the removal of the 14-alpha-methyl group from lanosterol, a key rate-limiting step in the production of ergosterol (PubMed: 25691602). This enzyme serves as the primary molecular target for the azole class of antifungal drugs, which are the cornerstone of treatment for cryptococcal infections. When azoles bind to the heme iron of CYP51, they inhibit its activity, leading to the depletion of ergosterol and the accumulation of toxic 14-alpha-methylated sterol intermediates (NCBI: PMC4324873). This disruption results in membrane dysfunction and the inhibition of fungal growth. However, the clinical utility of targeting CYP51 is increasingly threatened by the emergence of resistance, often driven by specific point mutations in the ERG11 gene or its overexpression (PubMed: 31653764). Additionally, because CYP51 is a member of the highly conserved cytochrome P450 superfamily, drugs targeting the fungal enzyme can sometimes cross-react with human P450 enzymes, leading to significant drug-drug interactions and potential side effects.

Other names

Erg11Cytochrome P450 51Sterol 14-alpha demethylaseERG11pCytochrome P450 family 51 subfamily A member 1

Inhibition of lanosterol 14-alpha demethylase by binding to the heme iron atom within the enzyme's active site, which prevents the oxidative demethylation of lanosterol and halts ergosterol production.