Pyruvate oxidation in ox heart

Abstract
The greatest activity of the pyruvate oxidation system by finely divided dialyzed ox heart suspensions was observed in the presence of inorganic phosphate, adenine nucleotide and fumarate added simultaneously. The presence of Mg + + was necessary to prevent irreversible inactivation of the enzyme during dialysis. Addition of catalytic amts. of fumarate (0.0005M) greatly increased both the O2 uptake and pyruvate disappearance. The pyruvate was completely oxidized to CO2 and water, the molecular ratio O2/pyruvate deduced by extrapolation from the exptl. data being 2.5 and R.Q. 1.2.