TY - JOUR
T1 - A model-free method for extracting interaction potential between protein molecules using small-angle X-ray scattering
AU - Sumi, Tomonari
AU - Imamura, Hiroshi
AU - Morita, Takeshi
AU - Nishikawa, Keiko
N1 - Funding Information:
This work was supported in part by Grant-in-Aid for Scientific Research (KAKENHI) (No. 25610121 ) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. H.I. and T.S. also thank Prof. Ryo Akiyama in Kyushu University for the useful discussion.
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/12
Y1 - 2014/12
N2 - A small-angle X-ray scattering has been used to probe protein-protein interaction in solution. Conventional methods need to input modeled potentials with variable/invariable parameters to reproduce the experimental structure factor. In the present study, a model-free method for extracting the excess part of effective interaction potential between proteinmolecules in solutions over an introduced hard-sphere potential by using experimental data of small-angle X-ray scattering is presented on the basis of liquid-state integral equation theory. The reliability of the model-free method is tested by the application to experimentally derived structure factors for dense lysozyme solutions with different solution conditions [Javid et al., Phys. Rev. Lett. 99, 028101 (2007), Schroer et al., Phys. Rev. Lett. 106, 178102 (2011)]. The structure factors calculated from themodel-free method agree well with the experimental ones. The model-free method provides the following picture of the lysozyme solution: these are the stabilization of contact-pair configurations, large activation barrier against their formations, and screened Coulomb repulsion between the charged proteins. In addition, the model-free method will be useful to verify whether or not a model for colloidal system is acceptable to describing protein-protein interaction.
AB - A small-angle X-ray scattering has been used to probe protein-protein interaction in solution. Conventional methods need to input modeled potentials with variable/invariable parameters to reproduce the experimental structure factor. In the present study, a model-free method for extracting the excess part of effective interaction potential between proteinmolecules in solutions over an introduced hard-sphere potential by using experimental data of small-angle X-ray scattering is presented on the basis of liquid-state integral equation theory. The reliability of the model-free method is tested by the application to experimentally derived structure factors for dense lysozyme solutions with different solution conditions [Javid et al., Phys. Rev. Lett. 99, 028101 (2007), Schroer et al., Phys. Rev. Lett. 106, 178102 (2011)]. The structure factors calculated from themodel-free method agree well with the experimental ones. The model-free method provides the following picture of the lysozyme solution: these are the stabilization of contact-pair configurations, large activation barrier against their formations, and screened Coulomb repulsion between the charged proteins. In addition, the model-free method will be useful to verify whether or not a model for colloidal system is acceptable to describing protein-protein interaction.
KW - DLVO model
KW - Integral equation
KW - Liquid state theory
KW - Lysozyme
KW - Protein solutions
KW - Protein-protein interaction
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U2 - 10.1016/j.molliq.2014.03.014
DO - 10.1016/j.molliq.2014.03.014
M3 - Article
AN - SCOPUS:84949135644
VL - 200
SP - 42
EP - 46
JO - Journal of Molecular Liquids
JF - Journal of Molecular Liquids
SN - 0167-7322
IS - PA
ER -