Mediation of glycosylated and partially-deglycosylated glucose oxidase of Aspergillus niger by a ferrocene-derivatised detergent.
Biochim Biophys Acta
; 1099(1): 91-101, 1992 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-1739731
ABSTRACT
A ferrocene-derivatised detergent, (11-ferrocenylundecyl) trimethylammonium bromide (FTMAB), when oxidised to the corresponding ferricinium ion, was found by electrochemical studies to be an effective electron acceptor for reduced glucose oxidase of Aspergillus niger (EC 1.13.4) and thus acts as a electron-transfer mediator between glucose oxidase and a working electrode held at a potential sufficiently positive to reoxidise reduced FTMAB. An increase in mediating activity was produced when FTMAB was present in concentrations above its critical micelle concentration. An 'enzyme electrode' was formed by adsorption of glucose oxidase and FTMAB surfactant on a graphite rod. The electrode functioned as an amperometric biosensor for glucose in phosphate-buffered saline solution. A mixed micelle of glucose oxidase and FTMAB, probably adsorbed on the electrode surface, appears to be advantageous for the amperometric determination of glucose. Additionally, glucose oxidase was treated with alpha-mannosidase. When this partially-deglycosylated glucose oxidase was incorporated in an enzyme electrode, a 100-fold increase in the second-order rate constant (k) for electron transfer between the enzyme and FTMAB was observed, together with increased current densities, with respect to the equivalent values for FTMAB and commercial glucose oxidase. The use of deglycosylated enzymes in biosensors is suggested.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aspergillus niger
/
Compostos Ferrosos
/
Detergentes
/
Glucose Oxidase
/
Compostos de Amônio Quaternário
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
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