title: Association behaviour of human erythrocyte phosphofructokinase. Dependence of molecular weight on enzyme concentration as analyzed by frontal gel chromatography.
abstract: Self-association of human erythrocyte phosphofructokinase has been studied at pH 8.0 and at 4 degrees C in the presence of 2 mM fructose 6-phosphate by means of frontal gel chromatography. Under these conditions the basic associating catalytically active species is the tetramer of the enzyme with a molecular weight of about 330000, the monomers of which having a molecular weight of 83000 as determined by sodium dodecyl sulphate electrophoresis. The experimental data have been compared with various models describing the enzyme association. The mode of association can sufficiently be described by assuming a weakly negative cooperative process in which the association constant of the nucleation step (association of two tetramers to an octamer) is larger than that of the following propagation steps. The geometry of association appears to be approximately spherical.
mesh_terms: D002850:Chromatography, Gel; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D046911:Macromolecular Substances; D008433:Mathematics; D008970:Molecular Weight; D010732:Phosphofructokinase-1 / Q000097:blood
chemical_list: D046911:Macromolecular Substances; D010732:Phosphofructokinase-1