title: Interaction of flavan-3-ol derivatives and different caseins is determined by more than proline content and number of proline repeats.
abstract: Interactions of Type A and B flavan-3-ol dimers (procyanidins) and several monomeric flavan-3-ols, with α-casein and β-casein, were investigated. Binding affinities measured were related to the ligands structure, including several properties (e.g. intrinsic flexibility (number of rotatable bonds) and hydrophobicity), and to the amino-acid composition of the caseins. A monomeric flavan-3-ol esterified with gallic acid (EGCG) had a five to ten times higher affinity to caseins compared to the non-galloylated dimeric flavan-3-ols. In this case, the larger number of rotatable bonds in EGCG might be accountable for this difference. Comparing flavan-3-ol dimers, intrinsic flexibility did not consistently promote interactions, as procyanidin A1 displayed a higher affinity to α-casein than the supposedly more flexible B-type dimers investigated. Despite its higher content of proline, compared to α-casein, β-casein did not always have a higher affinity for the ligands investigated (e.g. no interaction with procyanidin A1 detected). These results suggest that more factors than proline content and the number of proline repeats govern phenolic-casein interactions.
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Maxime C
authors.initials: MC
authors.lastname: Bohin
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: jean-paul.vincken@wur.nl.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vincken
authors.affiliation: Wageningen University, Laboratory of Biochemistry, P.O. Box 8128, 6700 ET Wageningen, The Netherlands.
authors.forename: Adrie H
authors.initials: AH
authors.lastname: Westphal
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Annelise M
authors.initials: AM
authors.lastname: Tripp
authors.affiliation: DSM Food Specialties, Alexander Fleminglaan 1, 2613 AX Delft, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Dekker
authors.affiliation: Unilever R&D, Olivier van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands.
authors.forename: Harry T W M
authors.initials: HT
authors.lastname: van der Hijden
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D002364:Caseins / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry; D011392:Proline / Q000737:chemistry*
chemical_list: D002364:Caseins; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; C404987:flavan-3-ol; D011392:Proline
keywords: Flavonoid–protein interaction; Fluorescence quenching; Ligand flexibility; Procyanidin purification; Ultrafiltration