title: Interaction between dietary bioactive peptides of short length and bile salts in submicellar or micellar state.
abstract: Bile salts act as steroidal detergents in the gut, and could also interact with peptides and improve their bioavailability, although the mechanism is unclear. The occurrence of direct interaction between milk bioactive peptides, Ile-Asn-Tyr-Trp, Leu-Asp-Gln-Trp, and Leu-Gln-Lys-Trp, and different bile salts in the submicellar or micellar state was investigated by intrinsic fluorescence measurement and dynamic light scattering, above the critical micellar concentration, the latter being determined by isothermal titration calorimetry. The peptides form aggregates, spontaneously. In the presence of bile salts, some released peptide monomers were bound to the micellar surface. The lack of hydrogen bonding involving the C12OH group of the steroid skeleton, and the acidic function of some bile salts, might promote the interaction with the peptides, as could the lack of the C12OH group, rather than that of the C7OH group. At submicellar concentrations, sodium taurochenodeoxycholate and taurodeoxycholate readily interacted with the most hydrophobic peptide Ile-Asn-Tyr-Trp.
authors.affiliation: Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (URAFPA), Vandœuvre-lès-Nancy F-54506, France; INRA, URAFPA USC-340, Vandœuvre-lès-Nancy F-54506, France.
authors.forename: Justine
authors.initials: J
authors.lastname: Guerin
authors.affiliation: UMR-7365 CNRS-Université de Lorraine, Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), Enzymologie Moléculaire et Structurale, Vandœuvre-lès-Nancy F-54506, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Kriznik
authors.affiliation: UMR-7365 CNRS-Université de Lorraine IMoPA, Ingénierie Moléculaire, Cellulaire, Thérapeutique et Glycosyltransférases, Vandœuvre-lès-Nancy F-54506, France.
authors.forename: Nick
authors.initials: N
authors.lastname: Ramalanjaona
authors.affiliation: Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (URAFPA), Vandœuvre-lès-Nancy F-54506, France; INRA, URAFPA USC-340, Vandœuvre-lès-Nancy F-54506, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Le Roux
authors.affiliation: Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (URAFPA), Vandœuvre-lès-Nancy F-54506, France; INRA, URAFPA USC-340, Vandœuvre-lès-Nancy F-54506, France. Electronic address: jean-michel.girardet@univ-lorraine.fr.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Girardet
mesh_terms: D001647:Bile Acids and Salts / Q000737:chemistry / Q000378:metabolism*; D002151:Calorimetry; D005453:Fluorescence; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances / Q000737:chemistry*; D008823:Micelles; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001647:Bile Acids and Salts; D046911:Macromolecular Substances; D008823:Micelles; D010446:Peptide Fragments
keywords: Bile salts; CMC; DLS; ITC; Milk whey proteins; Peptides; Tryptophan intrinsic fluorescence