Molecular Classification
Enzyme, Cytochrome P450, Monooxygenase
Other Names
Steroid 11β-hydroxylase, CYP11B1, mitochondrial
Disease Roles
Congenital adrenal hyperplasiaCushing’s diseaseFamilial hyperaldosteronism type I

Cytochrome P450 11B1 Overview

Cytochrome P450 11B1 (CYP11B1), also known as steroid 11β-hydroxylase, is a mitochondrial enzyme that belongs to the cytochrome P450 superfamily. It plays a critical role in the biosynthesis of glucocorticoids, particularly cortisol and corticosterone, within the adrenal cortex. It catalyzes the final steps in cortisol and corticosterone synthesis: Converts 11-deoxycortisol to cortisol and converts 11-deoxycorticosterone to corticosterone. Mutations in CYP11B1 cause congenital adrenal hyperplasia (CAH) due to 11β-hydroxylase deficiency, leading to excess androgen production and virilization. Overactivity or dysregulation can contribute to Cushing's disease through excessive cortisol production. The closest paralog is CYP11B2 (aldosterone synthase), which primarily produces aldosterone rather than cortisol/corticosterone but shares significant sequence similarity and overlapping substrate specificity.

Mechanism of Action

Inhibition of 11β-hydroxylation of steroid substrates

Biological Functions

Steroid hormone biosynthesis
Glucocorticoid production
Hydroxylation
Drug metabolism (minor role)

Disease Associations

Congenital adrenal hyperplasia
Cushing’s disease
Familial hyperaldosteronism type I

Safety Considerations

  • Potential for off-target effects on other steroidogenic enzymes due to active-site similarity (e.g., CYP11B2)
  • Superoxide production during metabolism

Interacting Drugs

Fadrozole