The indefinite self-association of lysozyme: consideration of composition-dependent activity coefficients

摘要: Abstract An improved iterative method for computing association constants from sedimentation equilibrium results obtained with self-interacting protein systems is presented which accounts the composition-dependence of activity coefficients all oligomeric species. The based on calculation virial covolume and charge considerations, statistical mechanical basis discussed in relation to DLVO theory. applied lysozyme diethylbarbiturate buffer pH 8.0 ionic strength 0.15 at 15°C. It shown that these results, encompassing a range total solute concentration up 19.7 g/liter are consistent self-association patterns comprising either monomer-dimer-trimer system or an isodesmic indefinite monomer, latter being favored. A firmer distinction between possibilities sought dependence weight-average partition coefficient, determined by frontal gel chromatography, (up 56.6 g/liter). This analysis ratio partitioning monomer mobile stationary phases. concluded governed single constant 4.61 × 102 liter/mole.