Glucose oxidase (GOx) is a key enzyme that catalyzes the oxidation of β-D-glucose to D-glucono-δ-lactone and hydrogen peroxide, playing an important role in glucose metabolism and redox biology. Assay kits for glucose oxidase enable sensitive, rapid, and reliable quantification of GOx activity in various biological and industrial samples.

Biochemical Role of Glucose Oxidase in Intermediary Metabolism

• Glucose Oxidation: GOx catalyzes the oxidation of glucose, converting it into D-glucono-δ-lactone, which spontaneously hydrolyzes to gluconic acid. This reaction helps regulate glucose availability and initiates downstream metabolic processes.
• Hydrogen Peroxide Production: The enzymatic reaction generates hydrogen peroxide (H₂O₂), a reactive oxygen species involved in cellular signaling and oxidative stress responses.
• Metabolic Integration: By controlling glucose oxidation and H₂O₂ levels, GOx indirectly influences glycolysis, the pentose phosphate pathway, and other metabolic routes, impacting energy production and cellular redox balance.

Principles of Glucose Oxidase Assay Kits

Glucose oxidase assay kits typically measure GOx activity based on its enzymatic reaction with glucose and oxygen, followed by detection of hydrogen peroxide or related products:

• Enzymatic Reaction: β-D-Glucose + O₂ → GOx → D-Glucono-δ-lactone + H₂O₂

• Colorimetric Assays: Hydrogen peroxide reacts with a chromogenic substrate in the presence of peroxidase to produce a colored compound measurable by absorbance (typically at 550–570 nm).
• Fluorometric Assays: Hydrogen peroxide or reaction intermediates generate fluorescent signals detected by microplate readers.
• Assay Format: Most kits use 96-well microplates for high-throughput screening, with simple protocols involving sample incubation with reagents followed by absorbance or fluorescence measurement.

Key Features of Glucose Oxidase Assay Kits

• Sensitivity: Detection limits as low as 0.002 U/L for fluorometric assays and 0.01 U/mL for colorimetric assays.
• Sample Types: Compatible with enzyme preparations, cell/tissue lysates, biological fluids, fermentation broths, and food products.
• Assay Time: Rapid protocols generally complete within 20–35 minutes at room temperature or 37°C.
• Stability: Reagents stable for over 6–12 months under recommended storage conditions.

Applications

• Metabolic Research: Quantification of GOx activity to study glucose metabolism and redox biology.
• Industrial Enzyme Production: Quality control of GOx in enzyme preparations and food additives.
• Biotechnology: Monitoring GOx in biosensor development and bioconversion processes.
• Pharmacology and Drug Discovery: Evaluating effects of compounds on GOx activity.
• Clinical Research: Investigating glucose regulation and oxidative stress in disease models.

Glucose oxidase assay kits provide robust, sensitive, and convenient tools for measuring glucose oxidase activity, facilitating research into intermediary metabolism and enzyme applications. Their enzymatic and detection principles closely reflect physiological glucose oxidation processes, enabling insights into metabolic regulation, enzyme production, and biotechnological innovations.