6533b85efe1ef96bd12c07e9
RESEARCH PRODUCT
Dynamical properties of myoglobin in an ultraviscous water-glycerol solvent investigated with elastic neutron scattering and FTIR spectroscopy
Fabio LibrizziAntonio CupaneAntonino Caliòsubject
Materials Chemistry2506 Metals and AlloysMaterials scienceAtomic and Molecular Physics and OpticHydrogenchemistry.chemical_element02 engineering and technologyNeutron scatteringCondensed Matter PhysicNeutron scattering010402 general chemistry01 natural sciencesQuantitative Biology::Subcellular Processeschemistry.chemical_compoundAmide bands; Fourier transform infrared spectroscopy; Mean square displacements; Neutron scattering; Protein dynamical transition; Electronic Optical and Magnetic Materials; Atomic and Molecular Physics and Optics; Condensed Matter Physics; Spectroscopy; Physical and Theoretical Chemistry; Materials Chemistry2506 Metals and AlloysMaterials ChemistrySide chainMoleculeAmide bandFourier transform infrared spectroscopyPhysical and Theoretical ChemistrySpectroscopySpectroscopyMean square displacementQuantitative Biology::BiomoleculesAmide bandsElectronic Optical and Magnetic MaterialProtein dynamical transitionEnergy landscapeFourier transform infrared spectroscopy021001 nanoscience & nanotechnologyCondensed Matter PhysicsMean Square DisplacementsAtomic and Molecular Physics and OpticsSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)0104 chemical sciencesElectronic Optical and Magnetic MaterialsMyoglobinchemistryFTIRChemical physics0210 nano-technologydescription
Abstract Proteins have distinctive dynamical properties, characterized by the fluctuations of protein molecules among the different minima of their energy landscape. These fluctuations, progressively activated for temperature values larger than ~180 K, lead to a steep increase in the temperature dependence of all measurable dynamical properties. This phenomenon is known as Protein Dynamical Transition and, in spite of the intense studies due to its importance in protein function and to the relation with the fascinating fundamental thermodynamics of complex systems, many aspects of it are not yet clearly understood. Among these, the relationship with the properties of the external solvent and the molecular details of the involved protein motions still need further investigations. We report here a comparative study of the Dynamical Transition in a Protein-Glycerol-Water system, from two different points of view: i) Elastic Neutron Scattering (ENS), which gives the Mean Square Displacements of the hydrogen atoms of the protein and is particularly sensitive to side chain motions; ii) Fourier Transform Infrared Spectroscopy (FTIR) in the Amide regions, which is sensitive mainly to the properties of the backbone atoms of the protein. The obtained results show an almost superimposable thermal behavior of protein backbone (FTIR data) and side chains (ENS data). Thus, in our experimental conditions, the Protein Dynamical Transition emerges as a unique thermodynamic process related to the properties of the external Glycerol/Water medium and implying a general softening of the whole protein molecule (backbone and side chains), which is a prerequisite for protein function.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-01-01 |