TY  - JOUR
A1  - Stadler, Andreas M.
A1  - Garvey, G. J.
A1  - Bocahut, A.
A1  - Sacquin-Mora, S.
A1  - Digel, Ilya
A1  - Schneider, G. J.
A1  - Natali, F.
A1  - Artmann, Gerhard
A1  - Zaccai, G.
T1  - Thermal fluctuations of haemoglobin from different species : adaptation to temperature via conformational dynamics
JF  - Journal of the Royal Society Interface
N2  - 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.
Y1  - 2012
U6  - http://dx.doi.org/10.1098/rsif.2012.0364
SN  - 1742-5689
VL  - 9
IS  - 76
SP  - 2845
EP  - 2855
PB  - The Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Eijck, Lambert van
A1  - Demmel, Franz
A1  - Artmann, Gerhard
A1  - Stadtler, Andreas Maximilian
T1  - Macromolecular dynamics in red blood cells investigated using neutron spectroscopy
JF  - Journal of the Royal Society Interface
Y1  - 2011
SN  - 1742-5689
VL  - 8
IS  - 57
SP  - 590
EP  - 600
PB  - The Royal Society
CY  - London
ER  -