A small-angle neutron scattering study of gamma-crystallins near their isoelectric point.
In this paper, a small-angle neutron scattering study of gammaII-crystallins near their isoelectric point is presented. The experiments were carried out using protein concentrations of 5.7-85.7 mg/ml at temperatures in the range 11 -60 degrees C. The experimental data were analyzed using an ellipsoidal model for intraparticle correlations and the mean spherical approximation for interparticle correlations. Our studies revealed that gammaII-crystallins have a thick hydration layer, which is possibly due to the special arrangement of polar and ionic groups on their surface. The temperature scan shows that, as a result of relatively strong attractive forces, clusters of two, three, or higher oligomers are present below 20 degrees C. Our results suggest that protein clusters, with a distinctive hydration layer, form a protein-rich phase that separates from a protein-lean phase as the temperature is decreased below some threshold value.
Petitt
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P
Chemical Engineering Department, University of Missouri-Rolla, 65401, USA.
Edwards
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ME
Forciniti
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D000818:Animals; D002417:Cattle; D003459:Crystallins / Q000737:chemistry*; D007526:Isoelectric Point; D046911:Macromolecular Substances; D009502:Neutrons; D012542:Scattering, Radiation; D012996:Solutions; D013696:Temperature; D014867:Water
D003459:Crystallins; D046911:Macromolecular Substances; D012996:Solutions; D014867:Water