3-ketosteroid reductase (3-KSR)

3-ketosteroid reductase is an enzyme of the oxidoreductase class (EC 1.1.1.270) that catalyzes the NADP+-dependent reduction of 3-keto steroids to 3β-hydroxy steroids, playing a crucial role in steroid biosynthesis and metabolism. It belongs to the aldo-keto reductase (AKR) superfamily, whose members act on a wide range of substrates including ketosteroids, prostaglandins, and aldehydes, contributing to both normal physiological processes and the detoxification of xenobiotics. Human AKR enzymes, particularly AKR1D1 (also described as delta4-3-ketosteroid-5-beta-reductase), are essential in bile acid synthesis and sex hormone metabolism; deficiencies can cause severe metabolic and liver disorders. AKR enzymes are implicated in cancer, drug resistance, and metabolic diseases, and are considered druggable targets with ongoing inhibitor development. "3-keto reductase" is a generic phrase that could technically refer to any reductase acting on a 3-keto group; in pharmacological and biochemical contexts, it usually indicates 3-ketosteroid reductase or related AKRs acting on steroidal substrates. Careful scientific identification (ideally including the specific EC number or gene/protein name) is needed for absolute specificity. "3-keto reductase" is a non-specific term. The most precise, accepted name is "3-ketosteroid reductase", classified as EC 1.1.1.270 (canonical), or by related AKR family members depending on substrate and context.

Other names

3-KSR3β-hydroxysteroid:NADP+ 3-oxidoreductase3-keto-steroid reductaseSome AKR enzymes are referred to as 3-keto reductase in the literature

Reduction of 3-keto groups on steroids, ketones, aldehydes, and related compounds using NADPH as a cofactor. Drug resistance in cancers may occur via enhanced reduction and metabolism by AKRs.