skvaleeniepoksidaasientsyymiä

Squalene epoxidase, also known as squalene monooxygenase, is an enzyme that plays a crucial role in the biosynthesis of cholesterol and other sterols in eukaryotic organisms. Its primary function is to catalyze the oxidative desaturation of squalene, a C30 triterpene, into 2,3-oxidosqualene. This reaction is the first committed step in the sterol biosynthetic pathway and is essential for the production of all steroid molecules.

The enzyme utilizes molecular oxygen and a reducing agent, typically NADPH, to carry out the epoxidation. It is a membrane-bound protein, usually located in the endoplasmic reticulum. The activity of squalene epoxidase is tightly regulated, and its expression levels can vary depending on cellular needs and hormonal signals. Dysregulation of this enzyme's activity has been implicated in various conditions, including certain fungal infections and dermatological disorders, as well as in the development of atherosclerosis. Inhibitors of squalene epoxidase are used as antifungal agents, such as terbinafine and naftifine, by disrupting ergosterol biosynthesis in fungi.