Description
The glucose oxidase enzyme (GOx) also known as notatin (EC number 1.1.3.4) is an oxido-reductase that catalyses the oxidation of glucose to hydrogen peroxide and D-glucono-δ-lactone. This enzyme is produced by certain species of fungi and insects and displays antibacterial activity when oxygen and glucose are present.
Abbr
GOD, Native (Aspergillus niger)
Applications
Glucose oxidase is widely used in the food and pharmaceutical industries as well as a major component of glucose biosensors.
Product Overview
Glucose oxidase from Aspergillus niger is a dimer consisting of 2 equal subunits with a molecular mass of 80 kDa each. Each subunit contains one flavin adenine dinulceotide moiety and one iron. The enzyme is a glycoprotein containing ~16% neutral sugar and 2% amino sugars. The enzyme also contains 3 cysteine residues and 8 potential sites for N-linked glycosylation. Glucose oxidase is capable of oxidizing D-aldohexoses, monodeoxy-D-glucoses, and methyl-D-glucoses at varying rates. The pH optimum for glucose oxidase is 5.5, while it has a broad activity range of pH 4-7. Glucose oxidase is specific for β-D-glucose with a KM of 33-110 mM. Glucose oxidase does not require any activators, but it is inhibited by Ag+, Hg2+, Cu2+, phenylmercuric acetate, and p-chloromercuribenzoate. It is not inhibited by the nonmetallic SH reagents: N-ethylmaleimide, iodoacetate, and iodoacetamide. Glucose oxidase can be utilized in the enzymatic determination of D-glucose in solution. As glucose oxidase oxidizes β-D-glucose to D-gluconolactate and hydrogen peroxide, horseradish peroxidase is often used as the coupling enzyme for glucose determination. Although glucose oxidase is specific for β-D-glucose, solutions of D-glucose can be quantified as α-D-glucose will mutorotate to β-D-glucose as the β-D-glucose is consumed by the enzymatic reaction.
Form
Type I, buffered aqueous solution; Solution in 50 mM potassium phosphate, 100 mM sodium acetate, 250 mM KCl, with 0.004% thimerosal, pH 4.5; Type II, Type VI, lyophilized powder. Type V, Lyophilized powder containing phosphate buffer salts and sodium chloride
Enzyme Commission Number
EC 1.1.3.4
Activity
Type I, <0.1 units/mg protein; Type II, 100,000-250,000 units/g solid (without added oxygen); Type III, 2,000-10,000 units/g solid (without added oxygen); Type IV, 15,000-50,000 units/g solid (without added oxygen); Type V, > 100,000 units/g solid (without added oxygen); Type VI, ~200 units/mg; Type VII, > 15,000 units/g solid (without added oxygen).
Contaminants
<0.1 units/mg protein catalase
Molecular Weight
160 kDa (gel filtration)
Unit Definition
One unit will oxidize 1.0 μmole of β-D-glucose to D-gluconolactone and H2O2 per min at pH 5.1 at 35°C, equivalent to an O2 uptake of 22.4 μl per min. If the reaction mixture is saturated with oxygen, the activity may increase by up to 100%.
Synonyms
EC 1.1.3.4; glucose oxyhydrase; corylophyline; penatin; glucose aerodehydrogenase; microcid; β-D-glucose oxidase; D-glucose oxidase; D-glucose-1-oxidase; β-D-glucose:quinone oxidoreductase; glucose oxyhydrase; deoxin-1; GOD; 9001-37-0; glucose oxidase enzyme; GOx; notatin; glucose oxidase