TY  - JOUR
AU  - Gaspar, A.M.
AU  - Busch, S.
AU  - Appavou, M.-S.
AU  - Haeussler, W.
AU  - Georgii, R.
AU  - Su, Y.
AU  - Doster, W.
TI  - Using polarization analysis to separate the coherent and incoherent scattering from protein samples
JO  - Biochimica et biophysica acta
VL  - 1804
SN  - 0006-3002
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - PreJuSER-8207
SP  - 76 - 82
PY  - 2010
N1  - A. M. Gaspar acknowledges the support given by Fundacao para Ciencia e Tecnologia in the form of a post-doc grant SFRH/BDP/17571/2004. The project was further supported by a grant of the Deutsche Forschungsgemeinschaft SFB 533.
AB  - Polarization analysis was used to separate experimentally the coherent and spin-incoherent nuclear static scattering functions, from a representative set of samples of interest for protein studies. This method had so far limited application in the study of amorphous materials, despite the relevance of the information that it provides. It allows, for instance, the experimental determination of the structure factor of materials containing a significant amount of hydrogen atoms, avoiding the contamination of measurements by a non-negligible incoherent background. Knowledge of the relative importance of the coherent and incoherent terms at different Q-values is also a pre-requisite for the interpretation of quasielastic neutron scattering experiments, performed at instruments in which the total dynamic scattering function is measured, such as conventional time-of-flight and backscattering spectrometers. Combining data from different instruments, it was possible to cover a wide Q-range, from the small-angle region (0.006<Q<0.04 A(-1)) to the wide-angle region (up to approximately 2.35 A(-1)). Quantitative information was obtained on the fraction of coherent to spin-incoherent scattering from different protein samples: deuterated and protonated protein powders at different hydration levels and solutions of protonated proteins in D(2)O at different concentrations. The results obtained are discussed in the context of the validity of the assumptions generally made when interpreting quasielastic neutron scattering experiments performed without polarization analysis.
KW  - Deuterium Oxide: chemistry
KW  - Hemoglobins: chemistry
KW  - Models, Chemical
KW  - Myoglobin: chemistry
KW  - Neutron Diffraction: methods
KW  - Phycocyanin: chemistry
KW  - Proteins: chemistry
KW  - Solutions
KW  - Water: chemistry
KW  - Hemoglobins (NLM Chemicals)
KW  - Myoglobin (NLM Chemicals)
KW  - Proteins (NLM Chemicals)
KW  - Solutions (NLM Chemicals)
KW  - Phycocyanin (NLM Chemicals)
KW  - Water (NLM Chemicals)
KW  - Deuterium Oxide (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:19595800
UR  - <Go to ISI:>//WOS:000272765200012
DO  - DOI:10.1016/j.bbapap.2009.06.024
UR  - https://juser.fz-juelich.de/record/8207
ER  -