Purification and characterization of oxalyl-coenzyme A decarboxylase from Oxalobacter formigenes.

Oxalyl-coenzyme A (oxalyl-CoA) decarboxylase was purified from Oxalobacter formigenes by high-pressure liquid chromatography with hydrophobic interaction chromatography, DEAE anion-exchange chromatography, and gel permeation chromatography. The enzyme is made up of four identical subunits (Mr, 65,000) to give the active enzyme (Mr, 260,000). The enzyme catalyzed the thiamine PPi-dependent decarboxylation of oxalyl-CoA to formate and carbon dioxide. Apparent Km and Vmax values, respectively, were 0.24 mM and 0.25 mumol/min for oxalyl-CoA and 1.1 pM and 0.14 mumol/min for thiamine pyrophosphate. The maximum specific activity was 13.5 microM oxalyl-CoA decarboxylated per min per mg of protein.