General description
Protocatechuate 3,4-Dioxygenase belongs to the non-heme iron family of enzymes. The active site of the enzyme contains Fe3+.
Application
Protocatechuate 3,4-Dioxygenase(PCD), from Pseudomonas sp., is used for the enzymatic determination of choline esterase when coupled with phydroxybenzoate hydroxylase. It is used to improve organic fluorophore-stability in single-molecule experiments and is used to study the metabolism of protocatechuate in Rhizobiaceae.
The enzyme has been used to create an oxygen scavenging system along with protocatechuate (PCA) and Trolox. The enzyme employs a nonheme iron center that catalyzes the conversion of PCA and molecular oxygen into β-carboxy-cis,cis-muconic acid, while the antioxidant Trolox suppresses slow blinking and photobleaching of cyanine dyes. It has been used in the preparation of imaging buffer along with DMB-BSA (dynein motility buffer-BSA), ATP and protocatechuate in single molecule motility assay.
Biochem/physiol Actions
Protocatechuate 3,4-Dioxygenase catalyzes the degradation of 3,4-dihydroxybenzoate (protocatechuate) into β-carboxy-cis,cis-muconate.
Physical properties
Structure : Protein with nonheme iron
Inhibitors : Ag+, Hg++, PCMB
Optimum pH : 9.0
Optimum temperature : 60−65°C
pH Stability : pH 7.0−9.0 (25°C, 72hr)
Thermal stability : below 50°C (pH 6.0, 1hr)
Unit Definition
One unit will oxidize 1.0 μmole of protocatechuate to 3-carboxy-cis,cis-muconate per min at pH 7.5 at 37 °C.
Physical form
Supplied as lyophilized powder.
Analysis Note
Protein determined by biuret.