Non-covalent binding of proteins to polyphenols correlates with their amino acid sequence

Kornél Nagy, Marie Claude Courtet-Compondu, Gary Williamson, Serge Rezzi, Martin Kussmann, Andreas Rytz

Research output: Contribution to journalArticleResearchpeer-review

33 Citations (Scopus)

Abstract

The present paper describes the assessment of non-covalent binding (NCB) between milk proteins and polyphenols and its correlation with the physicochemical parameters of proteins. A method based on ultrafiltration and liquid chromatography-tandem mass spectrometry was used to analyse free and non-covalently bound polyphenols (ligands) in mixtures with major milk proteins. Binding strength values of individual polyphenols were normalised to those obtained with quercitrin (quercetin-3-O-rhamnoside), used as a reference compound. NCB data acquired by experiments at pH 6.6 without any preliminary protein denaturation were correlated with the physicochemical parameters of ligands and proteins. Unsupervised multivariate analysis revealed that NCB of proteins clustered according to their family (caseins separated from albumins). Based on this model, a predictive relationship was observed between protein-polyphenol binding strength and primary/secondary structure parameters of the proteins e.g. number of charges, proline residues and extended strand. These results confirm that, under the investigated experimental conditions, the NCB between polyphenols and protein mixtures can be predicted and optimised based on the molecular structures.

Original languageEnglish
Pages (from-to)1333-1339
Number of pages7
JournalFood Chemistry
Volume132
Issue number3
DOIs
Publication statusPublished - 1 Jun 2012
Externally publishedYes

Keywords

  • Mass spectrometry
  • Non-covalent binding
  • Polyphenol
  • Principal Component Regression
  • Protein

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