Some properties of cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum.
Some properties of cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum.
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白腐真菌粉状孢子丝菌纤维二糖氧化酶的一些特性。
DOI：
10.1042/bj2280557
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
F. F. Morpeth
中科院分区：
文献类型：
--
作者：
F. F. Morpeth
用一种新的方法从白腐菌Sporotrichum puverulentum中提纯了纤维二糖氧化酶，使其达到均一。测定了该酶的碳水化合物和氨基酸组成。纤维二糖氧化酶含有FAD和细胞色素b辅基。根据沉淀平衡，该酶的相对分子质量为74400。这种酶是一种单体。光学、荧光和E.P.R.测定了氧化和还原纤维二糖氧化酶的光谱。对纤维二糖氧化酶底物专一性的初步研究表明，双糖甚至某些不溶性多糖是底物，而不是单糖。高浓度的纤维二糖对底物有很强的抑制作用。当氧是电子受体时，这种影响尤其明显。纤维二糖氧化酶在黄素蛋白中是不寻常的，因为它稳定红色阴离子黄素半喹酮并形成亚硫酸盐加合物，但似乎产生超氧阴离子作为其主要的还原氧产物。
Cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum has been purified to homogeneity by a new procedure. The carbohydrate and amino acid compositions of the enzyme have been determined. Cellobiose oxidase contains FAD and cytochrome b prosthetic groups. Mr of the enzyme has been estimated at 74400 by sedimentation equilibrium. The enzyme is a monomer. Optical, fluorescence and e.p.r. spectra of oxidized and reduced cellobiose oxidase have been determined. A preliminary investigation of the substrate specificity of cellobiose oxidase reveals that disaccharides and even some insoluble polysaccharides are substrates, but not monosaccharides. Strong substrate inhibition is seen at high concentrations of cellobiose. This effect is particularly marked when oxygen is the electron acceptor. Cellobiose oxidase is unusual among flavoproteins, since it stabilizes the red anionic flavin semiquinone and forms a sulphite adduct, yet appears to produce the superoxide anion as its primary reduced oxygen product.