Chemical Physics Letters, Vol.711, 8-14, 2018
Structures and interactions among lysozyme proteins below the isoelectric point in presence of divalent ions
Small angle neutron scattering study reveals that below the isoelectric point of the globular protein lysozyme and in the presence of different divalent (Mg2+, Ca2+ and Ba2+) and monovalent (Na+) ions, the long-range repulsive and the short-range attractive interactions decreases and increases respectively with the increase of salt concentration. In addition with these short- and long-range interactions, fractal aggregates also form even in pure lysozyme solution by a very small amount ( approximate to 0.5%). Protein-protein interactions are mostly dominated by the fractal structure factor only for Na+ and Mg2+ ions at higher salt concentrations as more aggregates are formed.