Journal Article

PreJuSER-23114

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Thermal fluctuations of haemoglobin from different species: adaptation to temperature via conformational dynamics

Stadler, A. M.FZJ* ; Garvey, C. J. ; Bocahut, A. ; Sacquin-Mora, S. ; Digel, I. ; Schneider, G. J.FZJ* ; Natali, F. ; Artmann, G. M. ; Zaccai, G.

2012
The Royal Society London

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Please use a persistent id in citations: doi:10.1098/rsif.2012.0364

Abstract: Thermodynamic stability, configurational motions and internal forces of haemoglobin (Hb) of three endotherms (platypus, Ornithorhynchus anatinus; domestic chicken, Gallus gallus domesticus and human, Homo sapiens) and an ectotherm (salt water crocodile, Crocodylus porosus) were investigated using circular dichroism, incoherent elastic neutron scattering and coarse-grained Brownian dynamics simulations. The experimental results from Hb solutions revealed a direct correlation between protein resilience, melting temperature and average body temperature of the different species on the 0.1 ns time scale. Molecular forces appeared to be adapted to permit conformational fluctuations with a root mean square displacement close to 1.2 Å at the corresponding average body temperature of the endotherms. Strong forces within crocodile Hb maintain the amplitudes of motion within a narrow limit over the entire temperature range in which the animal lives. In fully hydrated powder samples of human and chicken, Hb mean square displacements and effective force constants on the 1 ns time scale showed no differences over the whole temperature range from 10 to 300 K, in contrast to the solution case. A complementary result of the study, therefore, is that one hydration layer is not sufficient to activate all conformational fluctuations of Hb in the pico- to nanosecond time scale which might be relevant for biological function. Coarse-grained Brownian dynamics simulations permitted to explore residue-specific effects. They indicated that temperature sensing of human and chicken Hb occurs mainly at residues lining internal cavities in the β-subunits.

Keyword(s): Health and Life (1st) ; Health and Life (1st) ; Biology (2nd) ; J ; haemoglobin (auto) ; thermodynamic stability (auto) ; protein dynamics (auto) ; incoherent neutron scattering (auto) ; coarse-grained Brownian dynamics simulations (auto) ; circular dichroism (auto)

Note: Platypus RBC was provided by Nick Gust (Department of Primary Industries Tasmania, Australia) and Dominic Geraghty (University of Tasmania, Australia). Crocodile blood was provided by Crocodylus Park (Darwin, Australia). We thank Prof. Philip Kuchel (University of Sydney, Australia) for the use of his laboratory to purify crocodile and platypus Hb. Chicken blood was provided by Mario Suarez Avello and Josefa Garcia Alvarez. I. D. was sponsored by the BMBF Programme 'FHProfUnd' grant no. 1736X08. We also thank the Ministry of Innovation Science and Research of the federal state North Rhine-Westphalia for supporting Prof. Aysegul (Temiz) Artmann's project Dynamischer Strukturubergang bei Korpertemperaturen (FKZ: 800 009 04). A. M. S. thanks Prof. Georg Buldt and Prof. Dieter Richter for continuous support. This work is based on experiments performed at the Institute Laue-Langevin (ILL), Grenoble, France, and at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Garching, Germany.

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Contributing Institute(s):

1. Neutronenstreuung (ICS-1)
2. Neutronenstreuung (JCNS-1)
3. JCNS-FRM-II (JCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)

Experiment(s):

1. SPHERES: Backscattering spectrometer (NL6S)

Appears in the scientific report 2012

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Database coverage:
; BIOSIS Previews ; Current Contents - Life Sciences ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection ; Zoological Record

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