Biochemistry · Enzyme
Lipoprotein lipase (LPL) !
Lipoprotein lipase, anchored in capillaries, cuts the triglycerides of chylomicrons and VLDL so muscle and fat can take up the fatty acids.
Updated 2026-11-01
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Key facts
- Hydrolyses chylomicron and VLDL triglycerides to free fatty acids and monoacylglycerol.
- Adipose tissue, muscle and heart make it; it works on the luminal face of the endothelium, held by GPIHBP1.
- ApoC-II activates it; ApoC-III and ANGPTL3, 4 and 8 inhibit it.
- Insulin raises it in adipose tissue after meals; in fasting it prevails in muscle and heart.
- Heparin releases it from the endothelium into the blood (post-heparin activity).
Structure
- A 475-residue protein with a catalytic domain (Ser–Asp–His triad) and a lipid-binding C-terminal domain.
- Structure 6E7K shows human LPL bound to GPIHBP1, its endothelial transporter and anchor.
Regulation
- Insulin increases adipose LPL.
- ApoC-II activates it; ApoC-III and ANGPTL3, 4 and 8 inhibit it.
- In fasting, ANGPTL4 turns it off in adipose tissue and fat is routed to muscle.
Inhibitors and toxins
- Physiological inhibitors: ApoC-III, ANGPTL3, ANGPTL4
- Drugs against ApoC-III or ANGPTL3 free LPL from these brakes and lower triglycerides.
Clinical notes
- Its deficiency, or that of ApoC-II, GPIHBP1, LMF1 or ApoA-V, causes familial chylomicronaemia syndrome: very high triglycerides and pancreatitis.
- Poorly controlled diabetes lowers LPL and raises triglycerides.
- Fibrates activate PPAR-α, which increases LPL and lowers ApoC-III.
Related conditions
- Familial chylomicronemia syndrome (lipoprotein lipase deficiency)
- Acute pancreatitis
- Atherosclerosis and dyslipidaemia
- Type 2 diabetes mellitus
Related
- Chylomicron
- VLDL (very-low-density lipoprotein)
- Lipoprotein metabolism
- Apolipoprotein B (ApoB-100 and ApoB-48)
Test yourself
Think of the answer, then tap the question to see it.
Which apolipoprotein activates lipoprotein lipase?
ApoC-II, which chylomicrons and VLDL receive from HDL.
Where does LPL act?
On the luminal surface of capillaries in adipose tissue, muscle and heart, anchored by GPIHBP1.
How does insulin favour fat storage through LPL?
It raises adipose LPL after meals, so dietary fatty acids go into fat stores.
Educational information, not medical advice. For any symptom, see a health professional.
Sources: LPL: Lipoprotein lipase (human) (UniProt, 2026); LPL gene: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2026); 6E7K: Structure of the lipoprotein lipase GPIHBP1 complex that mediates plasma triglyceride hydrolysis (RCSB Protein Data Bank, 2026); Plasma lipoprotein remodeling (R-HSA-8963899) (Reactome, 2026).
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Representative model, for educational purposes only.