title: Binding of an Oligomeric Ellagitannin Series to Bovine Serum Albumin (BSA): Analysis by Isothermal Titration Calorimetry (ITC).
abstract: A unique series of oligomeric ellagitannins was used to study their interactions with bovine serum albumin (BSA) by isothermal titration calorimetry. Oligomeric ellagitannins, ranging from monomer to heptamer and a mixture of octamer-undecamers, were isolated as individual pure compounds. This series allowed studying the effects of oligomer size and other structural features. The monomeric to trimeric ellagitannins deviated most from the overall trends. The interactions of ellagitannin oligomers from tetramers to octa-undecamers with BSA revealed strong similarities. In contrast to the equilibrium binding constant, enthalpy showed an increasing trend from the dimer to larger oligomers. It is likely that first the macrocyclic part of the ellagitannin binds to the defined binding sites on the protein surface and then the "flexible tail" of the ellagitannin coats the protein surface. The results highlight the importance of molecular flexibility to maximize binding between the ellagitannin and protein surfaces.
authors.affiliation: Department of Chemistry, University of Turku , Vatselankatu 2, Turun Yliopisto, Turku FI-20014, Finland.
authors.forename: Maarit
authors.initials: M
authors.lastname: Karonen
authors.affiliation: Department of Chemistry, University of Turku , Vatselankatu 2, Turun Yliopisto, Turku FI-20014, Finland.
authors.forename: Marianne
authors.initials: M
authors.lastname: Oraviita
authors.affiliation: School of Agriculture, Policy and Development, University of Reading , Earley Gate, P.O. Box 236, Reading RG6 6AT, United Kingdom.
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
authors.affiliation: Department of Chemistry, University of Turku , Vatselankatu 2, Turun Yliopisto, Turku FI-20014, Finland.
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Salminen
authors.affiliation: School of Chemistry, Food and Pharmacy, University of Reading , Whiteknights, P.O. Box 224, Reading RG6 6AP, United Kingdom.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Green
mesh_terms: D001665:Binding Sites; D002151:Calorimetry / Q000379:methods*; D047348:Hydrolyzable Tannins / Q000378:metabolism*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D047348:Hydrolyzable Tannins; C013515:ellagitannin; D012710:Serum Albumin, Bovine
keywords: interactions; molecular size; polyphenol; protein; thermodynamics