Description_x000D_ General description_x000D_ The codA gene encodes the choline oxidase enzyme._x000D_ Application_x000D_ Choline oxidase from Sigma has been used in the enzymatic determination of choline in milk using a flow injection analysis (FIA) system with potentiometric detection.†_x000D_ Biochem/physiol Actions_x000D_ Choline oxidase from Arthrobacter sp. is a flavoprotein, which is a member of the GMC-oxidoreductase family. The enzyme catalyzes the four-electron-oxidation of choline to glycine betaine via the intermediate betaine aldehyde, in two sequential FAD-dependent reaction steps. The enzyme is useful for enzymatic determination of phosphatidylcholine by coupling with phospholipase D or determination of sphingomyelin by coupling with sphingomyelinase and for cholinesterase activity assays._x000D_ Choline oxidase, isolated from the soil bacterium Arthrobacter globiformis helps to transform choline to glycinebetaine (N-trimethylglycine)._x000D_ Unit Definition_x000D_ One unit will form 1 μmole of H2O2 with oxidation of 1 μmole of choline to betaine aldehyde per min at pH 8.0 at 37 °C. Note: During the conversion of choline to betaine by choline oxidase, 2 μmoles of H2O2 are produced for every μmole of choline._x000D_ Preparation Note_x000D_ It is recommended to reconstitute choline oxidase in phosphate buffer at pH 7.5 supplemented with 10mM EDTA. Reconstituted material can be stored at 2-8 °C for at least 2 weeks.