Indications of pH-induced conformational changes in phosphofructokinase from baker's yeast.

The partition of phosphorfructokinase (EC 2.7.1.11) from baker's yeast between the liquid phases of an aqueous biphasic systeem changes drastically in the pH interval 7-8, in contrast to other proteins. This abnormal behaviour is correlated to changes in sedimentation coefficient and binding capacity of the enzyme in this pH region. Since the molecular weight of phosphofructokinase does not change, these findings must reflect conformational changes in the enzyme molecule.