title: Role of dietary antioxidant (-)-epicatechin in the development of β-lactoglobulin fibrils.
abstract: Under specific physico-chemical conditions β-lactoglobulin is seen to form fibrils structurally highly similar to those that are formed by the amyloid-like proteins associated with neurodegenerative disorders, such as Alzheimer and Parkinson diseases. In the present study we provide insights on the possible role that the dietary flavonoid (-)-epicatechin plays on β-lactoglobulin fibril formation. Fibril formation is induced by keeping β-lactoglobulin solutions at pH2.0 and at a temperature of 80°C for 24h. Atomic Force Microscopy measurements suggest that, by adding (-)-epicatechin in the solution, fibrils density is visibly lowered. This last observation is confirmed by Fluorescence Correlation Spectroscopy experiments. With the use of Fourier Transform IR spectroscopy we monitored the relative abundances of the secondary structures components during the heating process. We observed that in the presence of (-)-epicatechin the spectral-weight exchange between different secondary structures is partially inhibited. Molecular Dynamics simulations have been able to provide an atomistic explanation of this experimental observation, showing that (-)-epicatechin interacts with β-lactoglobulin mainly via the residues that, normally in the absence of (-)-epicatechin, are involved in β-sheet formation. Unveiling this molecular mechanism is an important step in the process of identifying suitable molecules apt at finely tuning fibril formation like it is desirable to do in food industry applications.
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria, CREA-NUT, Via Ardeatina 546, 00178 Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Carbonaro
authors.affiliation: Dipartimento di Medicina Sperimentale e Chirurgia, Università Degli Studi di Roma "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Di Venere
authors.affiliation: Dipartimento di Fisica, Università degli studi di Roma "Tor Vergata" and INFN, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Filabozzi
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Maselli
authors.affiliation: Dipartimento di Fisica, Università degli studi di Roma "Tor Vergata" and INFN, Via della Ricerca Scientifica 1, 00133 Rome, Italy. Electronic address: minicozzi@roma2.infn.it.
authors.forename: V
authors.initials: V
authors.lastname: Minicozzi
authors.affiliation: Dipartimento di Fisica, Università degli studi di Roma "Tor Vergata" and INFN, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Morante
authors.affiliation: Dipartimento di Medicina Sperimentale e Chirurgia, Università Degli Studi di Roma "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Nicolai
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Nucara
authors.affiliation: Istituto di Struttura della Materia, CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Placidi
authors.affiliation: Dipartimento di Fisica, Università degli studi di Roma "Tor Vergata" and INFN, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Stellato
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D007782:Lactoglobulins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D056004:Molecular Dynamics Simulation; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D007782:Lactoglobulins; D002392:Catechin
keywords: (−)-Epicatechin; Aggregates; Fibrils; β-Lactoglobulin