Pyruvate Oxidase from microorganisms

Isoelectric point : 4.3
Michaelis constant : 3.4 X 10^-4M (Pyruvate)
Inhibitors : Fe^++,Zn⁺⁺,Cu⁺⁺,Ag⁺,Hg⁺⁺
Optimum pH : 5.7
Optimum temperature : 65^oC
pH Stability : pH 5.7 - 6.5 (25^oC, 20hr)
Thermal stability : below 45^oC (pH 6.0, 15min)

Pyruvate Oxidase from microorganisms has been used in the Amplex Red-based fluorescence assay for pyruvate. It has also been used in developing near real-time continuous detection system for pyruvate.

Pyruvate Oxidase (PoxB) converts pyruvate directly to acetate and CO₂. It is used to study pyruvate metabolism. It is used to study aerobic metabolism of bacterium, such as Lactobacillus plantarumand Streptococcus pneumoniae. Pyruvate Oxidase is used for enzymatic determination of pyruvate, GOT, and GPT in clinical analysis.

Pyruvate Oxidase oxidises pyruvate to form acetate, hydrogen peroxide and carbondioxide. Pyruvate oxidase requires flavin adenine dinucleotide (FAD), thiamine pyrophosphate (TPP) and magnesium as cofactors for its catalytic activity. Pyruvate oxidase is activated by the cofactor thiamine.

Pyruvate Oxidase consists of four subunits with identical molecular weights. PoxB reacts with certain aldehydes and phosphate can be replaced by arsenate. Oxygen as well as several artificial compounds can function as electron acceptors. Pyruvate Oxidase is activated by phospholipids as well as monomeric and micellar amphiphiles.

Lyophilized powder containing FAD and sugar as stabilizer

One unit will produce 1.0 μmole of H₂O₂ per min during the conversion of pyruvate and phosphate to acetylphosphate and CO₂ at pH 5.7 at 37 °C.