Characterization of fatty acid binding and transfer from Δ98Δ, a functional all-β abridged form of IFABP

Biochim Biophys Acta. 2014 Dec;1841(12):1733-40. doi: 10.1016/j.bbalip.2014.09.022.

Abstract

Intestinal fatty acid binding protein (IFABP) is an intracellular lipid binding protein whose specific functions within the cell 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. Cumulative evidence shows that Δ98Δ adopts a stable, monomeric and functional fold, with compact core and loose periphery. In agreement with previous results, this abridged variant indicates that the helical domain is-not necessary to preserve the general topology of IFABP's β-barrel and that the helix-turn-helix motif is a fundamental element of the portal region involved in ligand binding and protein-membrane interactions. 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 work highlights the importance of the β-barrel of IFABP for its specific functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylamide / metabolism
  • Animals
  • Cell Membrane / metabolism
  • Centrifugation
  • Fatty Acid-Binding Proteins / chemistry*
  • Fatty Acid-Binding Proteins / metabolism*
  • Fatty Acids / metabolism*
  • Phospholipids / metabolism
  • Protein Binding
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism
  • Protein Structure, Secondary
  • Rats
  • Spectrometry, Fluorescence
  • Sucrose / pharmacology
  • Terbium / metabolism

Substances

  • Fatty Acid-Binding Proteins
  • Fatty Acids
  • Phospholipids
  • Protein Isoforms
  • Terbium
  • Acrylamide
  • Sucrose