3-keto sterol reductase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: a 3-beta-hydroxyl sterol + NADP+ = a 3-keto sterol + NADPH + H+. [EC:1.1.1.270, GOC:mah, PMID:9811880]

3-keto sterol reductase activity is a crucial enzyme activity involved in the biosynthesis of sterols, a diverse group of lipids essential for various cellular processes. The enzyme catalyzes the reduction of a ketone group at the C-3 position of a sterol precursor molecule, specifically converting a 3-keto sterol to a 3beta-hydroxy sterol. This reaction is a critical step in the sterol biosynthetic pathway, leading to the production of cholesterol and other vital sterols.

The enzyme typically utilizes NADPH as a cofactor, donating a hydride ion to the ketone group and converting it to a hydroxyl group. This reduction step is stereospecific, resulting in the formation of the 3beta-hydroxy sterol isomer. The reaction proceeds through a series of steps, including substrate binding, hydride transfer, and product release.

The 3-keto sterol reductase enzyme plays a vital role in maintaining cellular sterol homeostasis. Its activity is tightly regulated to ensure proper sterol biosynthesis and prevent the accumulation of harmful sterol precursors. Dysregulation of this enzyme can lead to various pathological conditions, including hypercholesterolemia and other lipid metabolic disorders.

The molecular function of 3-keto sterol reductase activity is thus essential for maintaining cellular integrity and proper sterol metabolism, highlighting its critical role in human health.'
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Proteins (1)

Compounds (1)