THE EFFECTS OF ANIONS ON PHOSPHOGLYCERATE MUTASE

Chloride (5-100 mM) can activate the phosphoglycerate mutase reaction (3-PG .dblarw. 2-PG). I-, NO3- or higher Cl- inhibit the mutase reaction while allowing mixing of isotope form [32P]3-PG into a large pool of 2,3-bisphosphoglycerate. p-Hydroxybenzoate inhibits without causing isotope dilution. A number of anions stimulate the P-glycolate activated 2,3-bisphosphoglycerate phosphatase reaction of this enzyme. The same anions inhibit competitively phosphatase reaction of this enzyme. The same anions inhibit competitively with P-glycolate. A kinetic analysis relates the anion effects to changes in rates of association and dissociation of substrates.