Oxidases are enzymes that catalyze oxidation-reduction reactions using molecular oxygen as the electron acceptor. These enzymes play critical roles in cellular metabolism, energy production, detoxification pathways, and oxidative stress responses. AAT Bioquest offers comprehensive assay kits and substrates for quantifying oxidase activity across diverse research applications, including drug metabolism studies, antioxidant research, and enzyme kinetics.

Glucose oxidase is a dimeric flavoprotein that catalyzes the oxidation of β-D-glucose to hydrogen peroxide and D-glucono-1,5-lactone, which is subsequently hydrolyzed to gluconic acid. The enzyme requires flavin adenine dinucleotide (FAD) as a cofactor. Glucose oxidase is widely used for glucose determination in body fluids, food industry quality control, and biosensor development.

Amplite® Glucose Oxidase Assay Kits use the Amplite® Red substrate for dual detection modes—fluorimetric or colorimetric readout. The fluorimetric kit can detect as little as 0.05 mU/mL glucose oxidase, while the colorimetric version detects down to 12.5 mU/mL.

Glutamate oxidase belongs to the family of oxidoreductases that act on the CH-NH₂ group of donors with oxygen as an acceptor. This enzyme catalyzes the oxidative deamination of L-glutamate to α-ketoglutarate, ammonia, and hydrogen peroxide in the presence of water and oxygen.

Amplite® Fluorimetric Glutamate Oxidase Assay Kit provides an ultrasensitive method for measuring glutamate oxidase activity. The assay includes an amplification system using L-alanine and L-glutamate-pyruvate transaminase to significantly enhance H₂O₂ production, enabling detection of as little as 40 μU/mL glutamate oxidase.

Lysyl oxidase (LOX) is an extracellular enzyme that catalyzes the formation of aldehydes from lysine residues in collagen and elastin precursors. These aldehydes undergo spontaneous chemical reactions to form crosslinks, which are essential for stabilization of collagen fibrils and the integrity and elasticity of mature elastin. LOX activity is important in fibrosis research, cancer metastasis, and cardiovascular biology.

Amplite® Fluorimetric Lysyl Oxidase Assay Kit uses a proprietary LOX substrate that releases hydrogen peroxide, detected through HRP-coupled reactions. This method is much more sensitive than traditional tritium release assays and can detect sub-ng/mL lysyl oxidase.

Monoamine oxidases (MAOs) are flavin-containing amine oxidoreductases bound to the outer mitochondrial membrane. They catalyze the oxidation of monoamines and play a major role in inactivating neurotransmitters. MAO dysfunction has been associated with depression, schizophrenia, substance abuse, attention deficit disorder, and migraines. Two isoforms exist in humans: MAO-A and MAO-B.

Amplite® Fluorimetric Monoamine Oxidase Assay Kit measures MAO and semicarbazide-sensitive amine oxidase (SSAO) activities with high sensitivity, detecting as little as 10 μU/mL SSAO. The kit is suitable for blood samples and other biological specimens.

Xanthine oxidase (XO) catalyzes the oxidation of hypoxanthine to xanthine, and further to uric acid, playing an important role in purine catabolism. The enzyme is normally found in liver and jejunum. During severe liver damage, XO is released into blood, making it a useful biomarker for liver injury. Xanthine oxidase inhibitors are used therapeutically for gout treatment.

Amplite® Xanthine Oxidase Assay Kits measure enzyme activity through detection of hydrogen peroxide generated during purine oxidation. The fluorimetric kit can detect as little as 0.15 mU/mL xanthine oxidase; the colorimetric version detects 0.3 mU/mL.

Tyrosinase is a copper-containing oxidase that catalyzes the oxidation of phenolic compounds, including the conversion of tyrosine to DOPA and DOPA to dopaquinone in the melanin biosynthesis pathway. Tyrosinase assays are important for melanoma research, cosmetic ingredient screening, and food industry applications.