The maintenance/regulation of cellular levels of free fatty acids and fatty acyl-CoAs (the activated form of free fatty acids) is extremely important, as imbalances in lipid metabolism can have serious consequences for human health.
Free fatty acids can act as detergents to disrupt membranes so their generation is normally tightly regulated to states where they will be rapidly consumed or sequestered. Acyl-coenzyme A (CoA) thioesterases (ACOTs) hydrolyse medium- to long-chain fatty acyl-CoAs (of C12-C18 lengths) (MCFA-CoA, LCFA-CoA) to their corresponding free fatty acids (MCFA, LCFA) and CoASH. ACOTs located in peroxisomes are ACOT4, 6 and 8 (Hunt et al. 2006, Hunt et al. 2002).