title: Structure and Dynamics of Heteroprotein Coacervates.
abstract: Under specific conditions, mixing two oppositely charged proteins induces liquid-liquid phase separation. The denser phase, or coacervate phase, can be potentially applied as a system to protect or encapsulate different bioactive molecules with a broad range of food and/or medical applications. The optimization of the design and efficiency of such systems requires a precise understanding of the structure and the equilibrium of the nanocomplexes formed within the coacervate. Here, we report on the nanocomplexes and the dynamics of the coacervates formed by two well-known, oppositely charged proteins β-lactoglobulin (β-LG, pI ≈ 5.2) and lactoferrin (LF, pI ≈ 8.5). Fluorescence recovery after photobleaching (FRAP) and solid-state nuclear magnetic resonance (NMR) experiments indicate the coexistence of several nanocomplexes as the primary units for the coacervation. To our knowledge, this is the first evidence of the occurrence of an equilibrium between quite unstable nanocomplexes in the coacervate phase. Combined with in silico docking experiments, these data support the fact that coacervation in the present heteroprotein system depends not only on the structural composition of the coacervates but also on the association rates of the proteins forming the nanocomplexes.
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.
authors.forename: Paulo D S
authors.initials: PD
authors.lastname: Peixoto
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.|Laboratory of Research in Milk Products, Universidade Federal de Viçosa , BR-36570 Viçosa, Brazil.
authors.forename: Guilherme M
authors.initials: GM
authors.lastname: Tavares
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Croguennec
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Nicolas
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Hamon
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR CNRS 6226, Université de Rennes 1, CS 74205 Rennes, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Roiland
authors.affiliation: STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France.
authors.forename: Saïd
authors.initials: S
authors.lastname: Bouhallab
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D036681:Fluorescence Recovery After Photobleaching; D007781:Lactoferrin / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D062105:Molecular Docking Simulation; D046912:Multiprotein Complexes / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D055672:Static Electricity; D013816:Thermodynamics
chemical_list: D007782:Lactoglobulins; D046912:Multiprotein Complexes; D007781:Lactoferrin