Concentration-dependent migration in gel chromatography of reversibly polymerizing solutes: the osmotic behavior of polyacrylamide gels.
The osmotic behavior of gels derived from polyacrylamide has been measured in order to establish the validity of assuming linear concentration dependence of bead shrinkage upon osmotic pressure in quantitative studies of reversibly associating solutes by gel chromatography on Bio-Gel. The concentration dependence of elution volume predicted with due allowance for this osmotic shrinkage yields theoretical curves that provide good descriptions of experimental results obtained in chromatography of alpha-chymotrypsin on Bio-Gel P-30 equilibrated with acetate-chloride buffer, pH 3-86, 10.20; and also of bacterial alpha-amylase on Bio-Gel P-150 equilibrated with 0.10 M NaCl-0.015 M calcium acetate-0.010 M EDTA, pH 7.0. For the former system the osmotic effect has negligible consequences on the quantitative interpretation of the results. With the alpha-amylase system, however, consideration of the osmotic effect is necessary to obtain even a qualitative indication of the existence of the monomer-dimer equilibrium.
Tellam
R
R
Department of Biochemistry, University of Queensland, St. Lucia, Queensland 4067, Australia.
Winzor
D J
DJ