Fatty acid binding proteins are small cytoplasmic lipid binding proteins that are expressed in a tissue specific manner. FABPs bind free fatty acids, cholesterol, and retinoids, and are involved in intracellular lipid transport. Circulating FABP levels are used as indicators of tissue damage. Some FABP polymorphisms have been associated with disorders of lipid metabolism and the development of atherosclerosis.
FABP8 (fatty acid binding protein-8; also M [myelin]-FABP, P2 and PMP2) is a 15 kDa (predicted) member of the fatty acid binding protein family, calycin superfamily of molecules. It is found in Schwann cells, presumably on the cytoplasmic face of the plasma membrane where it may contribute to fatty acid transport across myelin. Functionally, FABP8 has a high affinity for U-shaped fatty acids such as oleic and palmitic acid. Human FABP8 is 132 amino acids (aa) in length and exhibits two layers of antiparallel β-strands that envelope a hydrophobic pocket for lipid binding. Arg107 plus Arg127-Ile128-Tyr129 participate in fatty acid binding. Full length human FABP8 shares 87% and 95% aa identity with mouse and rabbit FABP8, respectively.