Subunit structure of glucose oxidase from Aspergillus niger

O’Malley, James J.; Weaver, J L

doi:10.1021/bi00769a006

Cited by 75 publications

(29 citation statements)

References 18 publications

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“…The thermally denatured protein at 20°C has an intrinsic viscosity of 7.5 ml/g, and the chemically denatured protein has an intrinsic viscosity of 29.5 ml/g at the same temperature. This is in excellent agreement with the previously reported value of 30 ml/g for the chemically denatured state in 6 M GdmHCl (32). All viscosity measurements were done using the same concentration of the protein.…”

Section: Viscosity Of Native and Thermally And Chemically Denatured Ssupporting

confidence: 92%

“…The intrinsic viscosity of glucose oxidase was calculated from the reduced viscosity assuming highly diluted protein (Equation 4). The intrinsic viscosity of the native protein at 20°C was 4.12 ml/g, which closely agrees with the values reported previously (32,50). The thermally denatured protein at 20°C has an intrinsic viscosity of 7.5 ml/g, and the chemically denatured protein has an intrinsic viscosity of 29.5 ml/g at the same temperature.…”

Section: Viscosity Of Native and Thermally And Chemically Denatured Ssupporting

confidence: 90%

“…The partial specific volume was 0.714 cm 3 /g for GOX in buffer (31) and 0.704 cm 3 /g for GOX in buffer with GdmHCl (32). The viscosity and density correction of the aqueous solution of GdmHCl was made using published data (33).…”

Section: Methodsmentioning

confidence: 99%

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Irreversible Thermal Denaturation of Glucose Oxidase from Aspergillus niger Is the Transition to the Denatured State with Residual Structure

Žoldák

Zubrik

Musatov

et al. 2004

Journal of Biological Chemistry

127

105

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Glucose oxidase (GOX; ␤-D-glucose:oxygen oxidoreductase) from Aspergillus niger is a dimeric flavoprotein with a molecular mass of 80 kDa/monomer. Thermal denaturation of glucose oxidase has been studied by absorbance, circular dichroism spectroscopy, viscosimetry, and differential scanning calorimetry. Thermal transition of this homodimeric enzyme is irreversible and, surprisingly, independent of GOX concentration (0.2-5.1 mg/ml). It has an apparent transition temperature of 55.8 ؎ 1.2°C and an activation energy of ϳ280 kJ/mol, calculated from the Lumry-Eyring model. The thermally denatured state of GOX after recooling has the following characteristics. (i) It retains ϳ70% of the native secondary structure ellipticity; (ii) it has a relatively low intrinsic viscosity, 7.5 ml/g; (iii) it binds ANS; (iv) it has a low Stern-Volmer constant of tryptophan quenching; and (v) it forms defined oligomeric (dimers, trimers, tetramers) structures. It is significantly different from chemically denatured (6.67 M GdmHCl) GOX. Both the thermal and the chemical denaturation of GOX cause dissociation of the flavin cofactor; however, only the chemical denaturation is accompanied by dissociation of the homodimeric GOX into monomers. The transition temperature is independent of the protein concentration, and the properties of the thermally denatured protein indicate that thermally denatured GOX is a compact structure, a form of molten globulelike apoenzyme. GOX is thus an exceptional example of a relatively unstable mesophilic dimeric enzyme with residual structure in its thermally denatured state.Glucose oxidase (GOX 1 ; ␤-D-glucose:oxygen oxidoreductase, EC 1.1.3.4) is a flavoenzyme that catalyzes oxidation of ␤-Dglucose by molecular oxygen to ␦-gluconolactone, which subsequently hydrolyzes spontaneously to gluconic acid and hydrogen peroxide. The enzyme contains one tightly, noncovalently bound FAD cofactor per monomer and is a homodimer with a molecular mass of 160 kDa, depending on the extent of glycosylation (1). Glucose oxidase from Aspergillus niger is glycosylated by neutral sugars (mostly mannose-like sugars) and by amino sugars (2). Several reports find that the sugar content may vary from 11 up to 30% (3-5).GOX is of considerable commercial importance. The enzyme has applications in the food and fermentation industry, in the textile industry, and as a molecular diagnostic and analytical tool in medical and environmental monitoring applications (6 -10).The study of GOX and its applications is limited by its conformational instability. A significant effort has been made to increase the stability of GOX. It is known that both the thermal stability and the dynamic properties of the enzyme depend on its redox state (11, 12). Protein glycosylation affects the conformational dynamics of the active site and thus the activity of the enzyme (13). However, the way in which glycosylation affects the stability of GOX is not known. On the other hand, modification of the glucose oxidase surface by artificial long polyethylene-glycol ...

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Section: Viscosity Of Native and Thermally And Chemically Denatured Ssupporting

confidence: 92%

Section: Viscosity Of Native and Thermally And Chemically Denatured Ssupporting

confidence: 90%

See 1 more Smart Citation

Irreversible Thermal Denaturation of Glucose Oxidase from Aspergillus niger Is the Transition to the Denatured State with Residual Structure

Žoldák

Zubrik

Musatov

et al. 2004

Journal of Biological Chemistry

127

105

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“…Both glucose oxidase and gluconolactonase are located outside the plasma membrane and by activity staining and immunocytochemical staining glucose oxidase appears to be associated specifically with the cell wall in A. niger N400 (Witteveen et al, 1992). This is consistent with the observation that glucose oxidase from A. niger is glycosylated (Swoboda and Massey, 1965;O'Malley and Weaver, 1972), a general characteristic of fungal extracellular enzymes. The hydrogen peroxide generated by glucose oxidase inactivates the enzyme, probably through the oxidation of methionine residues (Kleppe, 1966).…”

Section: Gluconic Acidsupporting

confidence: 82%

Organic Acid Production by Filamentous Fungi

Magnuson

Lasure

2004

Advances in Fungal Biotechnology for Industry, Agriculture, and Medicine

228

162

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“…The enzyme is a flavincontaining globular glycoprotein with a molecular mass of about 155 kDa [1][2][3]. Glucose oxidase is of considerable industrial importance.…”

Section: Introductionmentioning

confidence: 99%

Cloning and DNA sequence analysis of the glucose oxidase gene from Aspergillus niger NRRL‐3

et al. 1989

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A cDNA library from Aspergillus niger strain NRRL‐3 enriched in sequences encoding the glucose oxidase was constructed. An 800 bp cDNA clone isolated from this library was used to screen 12 000 recombinant phages from an EMBL3 genomic library. A 15 kbp DNA segment isolated from this library contained the 1815 bp structural gene for glucose oxidase as well as a short 5′‐ and a longer 3′‐noncoding region. The deduced protein sequence was verified by partial peptide sequencing.

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Subunit structure of glucose oxidase from Aspergillus niger

Cited by 75 publications

References 18 publications

Irreversible Thermal Denaturation of Glucose Oxidase from Aspergillus niger Is the Transition to the Denatured State with Residual Structure

Irreversible Thermal Denaturation of Glucose Oxidase from Aspergillus niger Is the Transition to the Denatured State with Residual Structure

Organic Acid Production by Filamentous Fungi

Cloning and DNA sequence analysis of the glucose oxidase gene from Aspergillus niger NRRL‐3

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