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.
Human FABP-5, also known as epidermal fatty acid binding protein (E-FABP), is a 15 kDa member of a cytosolic fatty acid binding protein superfamily. It is associated with keratinocytes and adipocytes and is suggested to promote fatty acid availability to enzymes, protect cell structures from fatty acid attack, and target fatty acids to nuclear transcription factors. The amino acid sequence of human FABP5 is 80%, 81%, and 92% identical to that of mouse, rat, and bovine FABP5, respectively.