葡萄糖氧化酶 来源于黑曲霉

一种能氧化葡萄糖生成葡萄糖酸的氧化还原酶。该酶对β-D-葡萄糖表现很高的专一性。该酶需黄素腺嘌呤二核苷酸（FAD）作为辅酶，每个分子中含两个FAD。在蜂蜜中存在此种酶。许多微生物，特别是霉菌都能产生此种酶。常用曲霉、青霉菌等生产。 分子量：160 kDa（凝胶过滤） 等电点PI：4.2 消光系数：E1％=16.7（280纳米） 从黑曲霉（Aspergillus niger）分离的的葡糖氧化酶是二聚体，由2个相等的亚基单元组成，每个分子量为80 kDa。每个亚基单元含有一个黄素腺嘌呤的二核苷酸部分和一个铁。该酶是一种糖蛋白，含有?16%的中性糖和2%的氨基糖。该酶也包含3个半胱氨酸残基和8个潜在的N-连接糖基化位点。 葡萄糖氧化酶是能够以不同的速率氧化单脱氧-D-葡萄糖，D-己醛糖和甲基-D-葡萄糖。 葡萄糖氧化酶的最适pH为5.5，同时它有一个广阔的pH活性范围为4-7。葡萄糖氧化酶专一作用域β-D-葡萄糖（KM33-110 mM）。 葡萄糖氧化酶不要求任何活化因子，但它能被Ag+、Hg2+、Cu2+，醋酸苯汞和P – chloromercuribenzoate抑制 。它不被非金属SH试剂抑制：如N-乙基马来酰亚胺，吲哚乙酸，碘乙酰胺。 葡萄糖氧化酶也被用于溶液中酶法测定D-葡萄糖。由于葡萄糖氧化酶氧化β-D-葡萄糖，使其成为D-gluconolactate和过氧化氢，辣根过氧化物酶常被用作配对酶用于葡萄糖的测定。葡萄糖氧化酶被广泛应用于食品和医药工业，以及葡萄糖生物传感器的主要组成部分

Molecular Weight: 160 kDa (gel filtration) pI: 4.2 Extinction coefficient: E1% = 16.7 (280 nm) 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.
Glucose oxidase is widely used in the food and pharmaceutical industries as well as a major component of glucose biosensors