Biochemistry · Enzyme
β-Hydroxybutyrate dehydrogenase (BDH1) !
This enzyme turns acetoacetate into β-hydroxybutyrate in the liver, and back again in tissues that burn ketones.
Updated 2026-11-01
Key facts
- Acetoacetate + NADH ⇌ D-β-hydroxybutyrate + NAD⁺; reversible.
- Sits on the inner mitochondrial membrane and needs phosphatidylcholine to work.
- The β-hydroxybutyrate/acetoacetate ratio mirrors mitochondrial NADH/NAD⁺ (normally about 3:1).
- Also called
- D-3-hydroxybutyrate dehydrogenase
- EC number
- 1.1.1.30
- Genes
- BDH1
Regulation
- No major allosteric control: it follows the redox state (NADH/NAD⁺).
- Alcohol and hypoxia raise NADH and shift towards β-hydroxybutyrate.
Inhibitors and toxins
- No inhibitors in clinical use
Clinical notes
- In diabetic and alcoholic ketoacidosis the ratio climbs to 10:1, and the nitroprusside strip (which measures acetoacetate) underestimates ketones.
- During ketoacidosis treatment β-hydroxybutyrate turns back into acetoacetate and the strip can look more positive even as the patient improves.
Pathways
Related conditions
Related
- Acetoacetate (acetoacetic acid)
- β-Hydroxybutyrate
- NAD⁺ (nicotinamide adenine dinucleotide)
- Succinyl-CoA:3-ketoacid CoA transferase (SCOT)
Test yourself
Think of the answer, then tap the question to see it.
What sets the ratio of β-hydroxybutyrate to acetoacetate?
The mitochondrial NADH/NAD⁺ ratio, because the reaction is reversible and near equilibrium.
Why can the urine strip become more positive while ketoacidosis is being treated?
β-Hydroxybutyrate, which the strip misses, is converted back into acetoacetate, which it detects.
Which membrane lipid does β-hydroxybutyrate dehydrogenase need?
Phosphatidylcholine of the inner mitochondrial membrane.
Educational information, not medical advice. For any symptom, see a health professional.
Sources: BDH1: D-beta-hydroxybutyrate dehydrogenase, mitochondrial (human) (UniProt, 2026); Synthesis of Ketone Bodies (Reactome, 2026); Utilization of Ketone Bodies (Reactome, 2026).
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Representative model, for educational purposes only.