Description_x000D_ Application_x000D_ 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._x000D_ 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._x000D_ Packaging_x000D_ 100, 500, 1000 units in poly bottle_x000D_ 50 units in glass bottle_x000D_ Biochem/physiol Actions_x000D_ 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)._x000D_ Physical properties_x000D_ Isoelectric point: 4.1 ± 0.1_x000D_ Michaelis constants: 2.84 x 10¯3M (Choline), 5.33 x 10¯3M (Betaine aldehyde)_x000D_ Structure: One mol of FAD is covalently bound to mol of the enzyme_x000D_ Inhibitors: p-Chloromercuribenzoate, Cu++, Co++, Hg++, Ag+_x000D_ Optimum pH: 8.0 – 8.5_x000D_ Optimum temp: 40 – 45°C_x000D_ pH Stability: pH 7.0 – 9.0 (30°C, 2hr)_x000D_ Thermal stability: Below 37°C (pH 7.5, 10min)_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.