Fatty acid binding proteins

Definition

A family of small, soluble intracellular proteins that bind long-chain fatty acids and other hydrophobic ligands, facilitating their transport, storage, and metabolic trafficking within cells. In arthropods, FABPs play critical roles in lipid absorption, energy mobilization, and the regulation of metabolic signaling during development, diapause, and flight.

Etymology

From 'fatty acid' (carboxylic acids with long aliphatic chains, key energy substrates) + 'binding' (specific non-covalent association) + 'proteins' (polypeptide functional molecules).

Example

In the migratory locust Locusta migratoria, a cardiac FABP (cFABP) sequesters fatty acids released from the fat body during sustained flight, delivering them to the flight muscle mitochondria for β-oxidation and ATP production.

Synonyms

• FABPs
• intracellular lipid-binding proteins (iLBPs)
• fatty acid-binding proteins

Related Terms

• lipophorin
• Fat body
• beta-oxidation
• lipid metabolism
• Diapause
• Metamorphosis
• hexamerin
• apolipophorin III

Usage Notes

Distinguished from serum albumin (extracellular fatty acid transport) and from fatty acid transport proteins (FATPs, membrane-bound transporters). Insect FABPs are typically 14–15 kDa with a characteristic β-barrel structure; tissue-specific isoforms (heart, fat body, midgut) have distinct expression patterns. Not to be confused with fatty acid synthase or acyl-CoA binding proteins.