Picosecond dynamics in haemoglobin from different species: a quasielastic neutron scattering study
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Date
2014-10
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Background
Dynamics in haemoglobin from platypus (Ornithorhynchus anatinus), chicken (Gallus gallus domesticus) and saltwater crocodile (Crocodylus porosus) were measured to investigate response of conformational motions on the picosecond time scale to naturally occurring variations in the amino acid sequence of structurally identical proteins.
Methods
Protein dynamics was measured using incoherent quasielastic neutron scattering. The quasielastic broadening was interpreted first with a simple single Lorentzian approach and then by using the Kneller–Volino Brownian dynamics model.
Results
Mean square displacements of conformational motions, diffusion coefficients of internal dynamics and residence times for jump-diffusion between sites and corresponding effective force constants (resilience) and activation energies were determined from the data.
Conclusions
Modifications of the physicochemical properties caused by mutations of the amino acids were found to have a significant impact on protein dynamics. Activation energies of local side chain dynamics were found to be similar between the different proteins being close to the energy, which is required for the rupture of single hydrogen bond in a protein.
General significance
The measured dynamic quantities showed significant and systematic variations between the investigated species, suggesting that they are the signature of an evolutionary adaptation process stimulated by the different physiological environments of the respective protein. © 2014,Elsevier B.V.
Description
Keywords
Body temperature, Proteins, Amino acids, Hydrogen, Blood cells, Oxygen
Citation
Stadler, A. M., Garvey, C. J., Embs, J. P., Koza, M. M., Unruh, T., Artmann, G., & Zaccai, G. (2014). Picosecond dynamics in haemoglobin from different species: a quasielastic neutron scattering study. Biochimica et Biophysica Acta (BBA) - General Subjects, 1840(10), 2989-2999. doi:10.1016/j.bbagen.2014.06.007