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| Author(s): |
Andressa Ribeiro Pereira
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) |
| Defense date: | 2017-08-09 |
| Examining board members: |
Frank Nelson Crespilho;
Catia Cristina Capelo Ornelas Megiatto
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| Advisor: | Frank Nelson Crespilho |
| Abstract | |
The direct electrochemistry of redox enzymes is dependent on the distance between the active centers of the protein and the electrode surface, and also on the efficiency in the immobilization of these enzymes on the electrodic surface. Thus, the synthesis of more hydrophobic enzymes could lead to better interaction between the redox enzymes and the solid electrode surfaces, such as carbon electrodes. In this study, it was proposed a chemical route to obtain oligomerized glucose oxidase (Ol-GOx), aiming to improve the interaction between the enzyme and the surface of carbon fibers, since oligomerized proteins have their hydrophobic chains exposed. After structural characterization, it was concluded that Ol-GOx is formed by 10 dimeric units of native GOx with a hydrodynamic radius corresponding to approximately 96 nm. By cyclic voltammetry, it was studied the direct electron transfer (DET) between the flavin adenine dinucleotide (FAD) cofactor and the surface of carbon fibers, where it was observed an increase of 7-fold in the faradaic currents in comparison to that observed for native GOx. Besides, bioelectrocatalytic properties are 30% improved, when analyzed the glucose oxidation by cyclic voltammetry. It was also concluded that the greater the β-sheet content in protein structure, the higher the DET observed between the enzyme and the carbon fibers surface. (AU) | |
| FAPESP's process: | 13/19908-2 - Bioelectrochemical study of the deglycosylated glucose oxidase enzyme for application in biofuel cells |
| Grantee: | Andressa Ribeiro Pereira |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |