| Abstract: | The specific elution of rabbit skeletal muscle phosphofructokinase (PFK) from DEAE-cellulose is studied in the linear gradient of different allosteric ligands. Citrate and fructose-6-phosphate elute PFK at concentrations of 1.0 and 2.5 mM respectively, i.e. without increasing the ionic strength of the starting buffer (similar to 0.12). The specificity of elution is confirmed by comparison of the ionic strength of these solutions with that of buffer eluting PFK in buffer gradient (mu=0.17) as well as by comparison with the eluting ability of other ligands. Fructose-1,6-diphosphate elutes PFK only at the concentration of 5.5 mM which corresponds to the ionic strength 0.17. MgATP and AMP are inefficient as specific eluents whereas ATP and ADP elute only a small part of PFK with concomitant substantial increase of the ionic strength (up to 0.17--0.18). These results are discussed in terms of a charge compensation mechanism as a result of the displacement of PFK conformers equilibrium under the influence of the allosteric ligands. |
