1. Characterization of fatty acid binding and transfer from Δ98Δ, a functional all-β abridged form of IFABP.
- Author
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Sawicki LR, Guerbi MX, Falomir Lockhart LJ, Curto LM, Delfino JM, Córsico B, and Franchini GR
- Subjects
- Acrylamide metabolism, Animals, Cell Membrane metabolism, Centrifugation, Phospholipids metabolism, Protein Binding, Protein Isoforms chemistry, Protein Isoforms metabolism, Protein Structure, Secondary, Rats, Spectrometry, Fluorescence, Sucrose pharmacology, Terbium metabolism, Fatty Acid-Binding Proteins chemistry, Fatty Acid-Binding Proteins metabolism, Fatty Acids metabolism
- 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.
- Published
- 2014
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