3β-hydroxysteroid-Δ⁸,⁷-isomerase

3β-hydroxysteroid-Δ⁸,⁷-isomerase, also known as emopamil-binding protein (EBP) or cholestenol Δ⁸–Δ⁷ isomerase, is a membrane-associated enzyme that catalyzes the isomerization of Δ⁸-sterols to Δ⁷-sterols in the cholesterol biosynthesis pathway, specifically in the postlanosterol segment of the pathway[2]. This enzyme forms part of the microsomal antiestrogen binding site (AEBS) complex within the endoplasmic reticulum and is essential in converting sterol intermediates downstream of lanosterol towards cholesterol[2]. EBP is a well-validated therapeutic target in rare congenital disorders of sterol metabolism (such as Conradi–Hünermann syndrome) and, as a component of the AEBS complex, has relevance in the pharmacology of certain antiestrogens (including tamoxifen)[2]. Disruption of this enzyme leads to accumulation of atypical sterol intermediates and disturbed cholesterol homeostasis. If more detailed molecular functions or clinical roles are needed, they would require additional disease-targeted reviews or genetic studies. Overall, this protein is a recognized therapeutic target in some disease contexts and a critical enzyme in cholesterol metabolism.

Other names

Emopamil-binding protein (EBP)Cholestenol Δ⁸–Δ⁷ isomerase3-beta-hydroxysteroid-Delta(8),Delta(7)-isomerase

Enzyme inhibition (targeted by drugs disrupting cholesterol biosynthesis or AEBS/ChEH function), Modulation of cholesterol or sterol biosynthetic pathway