Intracellular lipid transport:: Structure-function relationships in intracellular lipid binding proteins

CÓRSICO, B.

Future Lipidology

Año: 2006 p. 615 - 622

1746-0875

Fatty acid binding proteins (FABPs) belong to a superfamily of intracellular lipid binding proteins of low molecular weight with the putative general function of lipid trafficking. The precise physiological functions of these proteins are still unclear, but their importance in intracellular transport and targeting of fatty acids (FA) to specific membranous organelles and metabolic pathways is hypothesized. Different members of the FABP family transfer fatty acids to phospholipid bilayers via distinct kinetic mechanisms. Fatty acid-binding proteins share a common tertiary structure consisting of ten antiparallel β-strands that form a β-barrel, which is capped by two short a-helices arranged as a helix-turn-helix segment. It has been shown that the a-helical region of FABPs is involved in membrane interactions, and appears to play a primary role, determining the mechanism of transfer of fatty acid from FABPs to membranes. Membrane composition is a very important feature that modulates fatty acid transfer, and electrostatic and hydrophobic interactions between protein and membrane appear to participate in the transfer process. The structural elements underlying transfer of a fatty acid from FABPs to membranes could have important physiological consequences as they may dictate the fatty acid trafficking patterns within the cell. Interactions with other proteins have been reported for some FABPs in different tissues, most of them suggesting specific trafficking functions of these proteins to and from specific organelles and metabolic pathways. The progress of in vivo studies in cell culture and whole animals was also analyzed.