title: Investigation into the Relaxation Dynamics of Polymer-Protein Conjugates Reveals Surprising Role of Polymer Solvation on Inherent Protein Flexibility.
abstract: Fully biodegradable protein-polymer conjugates, namely, MBP-PMeEP (maltose binding protein-poly methyl-ethylene phosphonate), have been investigated in order to understand the role of polymer solvation on protein flexibility. Using elastic and quasi-elastic incoherent neutron scattering, in combination with partially deuterated conjugate systems, we are able to disentangle the polymer dynamics from the protein dynamics and meaningfully address the coupling between both components. We highlight that, in the dry state, the protein-polymer conjugates lack any dynamical transition in accordance with the generally observed behavior for dry proteins. In addition, we observe a larger flexibility of the conjugated protein, compared to the native protein, as well as a lack of polymer-glass transition. Only upon water hydration does the conjugate recover its dynamical transition, leading to the conclusion that exclusive polymer solvation is insufficient to unfreeze fluctuations on the picosecond-nanosecond time scale in biomolecules. Our results also confirm the established coupling between polymer and protein dynamics in the conjugate.
authors.affiliation: CNR-IOM (Italy), c/o Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156-38042 Grenoble, France.|Institut Lumière Matière, Université de Lyon , Campus LyonTech-La Doua, Bâtiment Kastler, 10 rue Ada Byron, 69622 Villeurbanne CEDEX, France.
authors.forename: Daniela
authors.initials: D
authors.lastname: Russo
authors.affiliation: Physics Department, Università degli Studi di Perugia , Via Alessandro Pascoli, 06123 Perugia, Italy.|LIPhy, CNRS, and Université Grenoble Alpes, 140 Rue de la Physique, 38402 Saint-Martin-d'Hères, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Plazanet
authors.affiliation: Laboratoire Léon Brillouin, CEA and CNRS, Bât. 563 CEA Saclay, 91191 Gif Sur Yvette Cedex, France.
authors.forename: José
authors.initials: J
authors.lastname: Teixeira
authors.affiliation: ILL Deuteration Laboratory, Partnership for Structural Biology , 71 avenue des Martyrs, CS 20156-38042 Grenoble, France.|Life Sciences Group, Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156-38042 Grenoble, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Moulin
authors.affiliation: ILL Deuteration Laboratory, Partnership for Structural Biology , 71 avenue des Martyrs, CS 20156-38042 Grenoble, France.|Life Sciences Group, Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156-38042 Grenoble, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Härtlein
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Frederik R
authors.initials: FR
authors.lastname: Wurm
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Steinbach
mesh_terms: D033363:Neutron Diffraction / Q000379:methods; D009502:Neutrons; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D011108:Polymers; D011506:Proteins; D014867:Water