Application

Choline oxidase from Alcaligenes sp. has been used to evaluate choline biosensors constructed with chitinous membranes. The enzyme has also been used to analyse the photoreaction of choline oxidase with covalently bound flavin, using spectroscopic techniques. Furthermore, the product can be used for cholinesterase activity and phospholipid determination assays.

Choline oxidase from Alcaligenes sp. has been used in a study to investigate a choline biosensor constructed with chitinous membrane and its application in measuring cholinesterase inhibitory activities. Choline oxidase from Alcaligenes sp. has also been used in spectroscopic studies on the photoreaction of choline oxidase with covalently bound flavin.

Biochem/physiol Actions

Choline oxidase catalyzes the four-electron oxidation of choline to glycine-betaine, with betaine-aldehyde as the intermediate and molecular oxygen as th eprimary electron acceptor. The enzyme can also accept betaine-aldehyde as a substrate. This allows the study of the reaction mechanism for the conversion of choline to the aldehyde intermediate, & of betaine-aldehyde to glycine-betaine. The enzyme is a flavoprotein with a molecular weight of approx. 72,000 Da (gel filtration) or 66,000 Da (SDS gel electrophoresis).

Packaging

100, 500, 1000 units in poly bottle

50 units in glass bottle

Physical properties

Isoelectric point: 4.1 ± 0.1Michaelis constants: 2.84 x 10¯³M (Choline), 5.33 x 10¯³M (Betaine aldehyde)Structure: One mol of FAD is covalently bound to mol of the enzymeInhibitors: p-Chloromercuribenzoate, Cu⁺⁺, Co⁺⁺, Hg⁺⁺, Ag⁺Optimum pH: 8.0 – 8.5Optimum temp: 40 – 45°CpH Stability: pH 7.0 – 9.0 (30°C, 2hr)Thermal stability: Below 37°C (pH 7.5, 10min)

Unit Definition

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.