Characterization of fatty acid binding and transfer from ∆98∆, a functional all-β abridged form of IFABP

RODRIGUEZ SAWICKI L; GUERBI MX; FALOMIR LOCKHART LJ; CURTO L; DELFINO JM; CÓRSICO B; FRANCHINI GR

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 1841 p. 1733 - 1740

1388-1981

Intestinal fatty acid binding protein (IFABP) is an intracellular lipid binding protein whose specific functions are still uncertain. An abbreviated version of IFABP encompassing residues 29-126, dubbed Δ98Δ is a stable product of limited proteolysis with clostripain of holo-IFABP. Previous results using rationally designed helix-less variants indicate that the helical domain is not necessary to preserve the general topology of IFABP´s β-barrel and it is accepted that the helix-turn-helix motif is a fundamental element of the portal region involved in ligand binding and protein-membrane interactions. Cumulative evidence shows that Δ98Δ adopts a stable, monomeric fold, with compact core and loose periphery. Results presented here suggest that Δ98Δ binds fatty acids with affinities lower than IFABP but higher than those shown by previous helix-less variants, shows a ´diffusional´ fatty acid transfer mechanism and it interacts with artificial membranes. This highlights the importance of the β-barrel of IFABP for its specific functions.