C5896

Choline Oxidase from Alcaligenes sp.

lyophilized powder, ≥10 units/mg solid

• Synonym(s): Choline: oxygen 1-oxidoreductase
• CAS Number: 9028-67-5
• EC Number: 1.1.3.17 (BRENDA, IUBMB)
• EC Number: 232-840-0
• MDL number: MFCD00130787
• UNSPSC Code: 12352204
• NACRES: NA.54

Properties

• form: lyophilized powder
• Quality Level: 200
• specific activity: ≥10 units/mg solid
• mol wt: ~95 kDa
• technique(s): cell based assay: suitable
• suitability: suitable for assay of choline; suitable for molecular biology
• storage temp.: −20°C

Description

Application

Choline oxidase from Alcaligenes sp. has been used:

• in a study to investigate a choline biosensor constructed with a chitinous membrane and its application in measuring cholinesterase inhibitory activities
• has also been used in spectroscopic studies on the photoreaction of choline oxidase with covalently bound flavin.
• as a component of phosphate buffer saline (PBS) buffer for measurement of choline acetyltransferase (ChAT) activity in brain tissue homogenates
• to measure the choline generated by autotaxin (ATX) by ATX activity assay and phospholipase-D (PLD) by PLD activity assay

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).

Physical properties

Isoelectric point:4.1 ± 0.1
Michaelis 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 enzyme
Inhibitors:p-Chloromercuribenzoate, Cu⁺⁺, Co⁺⁺, Hg⁺⁺, Ag⁺
Optimum pH:8.0 – 8.5
Optimum temp:40 – 45°C
pH 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.

Safety Information

• Pictograms: GHS08
• Signal Word: Danger
• Hazard Statements: H334
• Precautionary Statements: P261 - P284 - P501
• Hazard Classifications: Resp. Sens. 1
• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves