Model of lysozyme (model 2) at its isoelectric point at with 16 positive charges (shown in black) and 16 negative charges (in gray).
Comparison of the reduced potential of mean force as obtained by the Asakura-Oosawa theory [Eq. (3)] and by the Monte Carlo simulations. The calculation applies to mixtures of uncharged proteins (model 1, ) at and oligomers at . Symbols denote the Monte Carlo data and the line results of the Asakura-Oosawa theory.
Pair-distribution functions ; symbols represent Monte Carlo data and lines the MSA calculation. Results for pure aqueous solution of uncharged proteins at concentration are shown by full squares. The results after addition of uncharged hard spheres of the size of the monomers are denoted by open circles and full line; . The radius of the protein molecule was and that of hard sphere particles .
Pair-distribution functions of charged proteins at a concentration and at different concentrations of uncharged monomers. Results in panel (a): full squares (full line) belong to pure protein solution, while open circles (dotted line) show the data obtained after addition of hard sphere particles with at concentration . (b) The same protein solution but containing a different concentration of hard sphere particles; . Symbols refer to Monte Carlo data and lines to the MSA results again.
Pair-distribution functions of charged proteins at a concentration for different degrees of polymerization. Open circles correspond to , full circles to , and open triangles to at . In panel (a) monomers are uncharged, (b) every monomer unit is charged; . (c) Comparison between MC (open circles) and polymer MSA results (full line) for uncharged oligomers . (d) Theoretical trends for uncharged (full line) and partially charged; (dotted line) oligomers with .
Monte Carlo pair-distribution functions for the model lysozyme molecules with zero net charge (model 2) at (full squares) and after addition of uncharged monomers (open circles) and chains with (full circles) at .
Monte Carlo pair-distribution functions for the model lysozyme molecules with the net charge at (full squares); (i) uncharged (open circles) or (ii) charged (full circles) oligomers with at a concentration .
Cluster size distribution function for the neutral (net charge is zero) lysozyme molecules (model 2) at (full curve) and after addition of uncharged oligomer chains with (dashed line) and (dotted line) at .
Scattered intensity: Experimental data (left axis) for a solution with the lysozyme molecules having net charge at , and after addition of dextran in phosphate buffer (Ref. 28). Simulation data (right axis) are for a lysozyme solution (model 2, ) at and after addition of uncharged oligomers with at . Empty symbols denote the experiments and full symbols simulations. Circles refer to pure lysozyme solutions and squares to the lysozyme-dextran mixtures. Dotted lines are drawn to guide the eye.
Article metrics loading...
Full text loading...