Cytochrome P450 11B1 (CYP11B1) (CYP11B1)

Cytochrome P450 11B1 (CYP11B1), also known as 11-beta-hydroxylase, is a mitochondrial enzyme primarily expressed in the adrenal cortex that catalyzes the final step of cortisol biosynthesis (UniProt: P15538). It converts 11-deoxycortisol into cortisol, the primary glucocorticoid involved in the stress response, metabolism, and immune regulation (StatPearls: Physiology, Cortisol). Dysregulation of this enzyme or the broader hypothalamic-pituitary-adrenal (HPA) axis can lead to conditions such as Cushing's syndrome, characterized by excess cortisol, or congenital adrenal hyperplasia (NIH: Genetics Home Reference). In therapeutic contexts, CYP11B1 is a major target for steroidogenesis inhibitors designed to reduce pathological cortisol production (PubMed: PMC6075634). Drugs like osilodrostat and metyrapone bind to the heme group of the enzyme, effectively blocking its catalytic activity and lowering systemic cortisol levels (FDA: Isturisa Label). Clinical management of patients on these therapies requires careful monitoring of cortisol levels to avoid iatrogenic adrenal insufficiency or adrenal crisis (Journal of Clinical Endocrinology & Metabolism). Additionally, inhibition of CYP11B1 can lead to the accumulation of upstream precursors, which may be shunted into androgenic pathways, potentially causing side effects like hirsutism or acne in female patients (StatPearls: Cushing Syndrome).

Other names

11-beta-hydroxylaseSteroid 11-beta-monooxygenaseCPN1P450C11Cytochrome P450 family 11 subfamily B member 1

Inhibition of the enzyme Cytochrome P450 11B1, which catalyzes the final step of cortisol synthesis by converting 11-deoxycortisol to cortisol, thereby reducing systemic cortisol levels.