Inhibited enzymatic reaction of crosslinked lactate oxidase through a pH-dependent mechanism

Lactate oxidase (LOx), recognized to selectively catalyze the lactate oxidation in complex matrices, has been highlighted as preferable biorecognition element for the development of lactate biosensors. In a previous work, we have demonstrated that LOx crosslinking on a modified screen-printed electr...

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Detalhes bibliográficos
Autores: Cunha Silva, Hugo, Pires, Filipa Velez, Cabral, A. Cristina Dias, Arcos Martínez, Julia
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Recursos:Universidad de Burgos (UBU)
Repositorio:Repositorio Institucional de la Universidad de Burgos (RIUBU)
OAI Identifier:oai:riubu.ubu.es:10259/5348
Acesso em linha:http://hdl.handle.net/10259/5348
Access Level:acceso abierto
Palavra-chave:Lactate oxidase inhibition
Amperometric biosensor
Lactic acid
Fluorescence spectrometry
Dynamic light scattering
Química analítica
Chemistry, Analytic
Descrição
Resumo:Lactate oxidase (LOx), recognized to selectively catalyze the lactate oxidation in complex matrices, has been highlighted as preferable biorecognition element for the development of lactate biosensors. In a previous work, we have demonstrated that LOx crosslinking on a modified screen-printed electrode results in a dual range lactate biosensor, with one of the analysis linear range (4 to 50 mM) compatible with lactate sweat levels. It was advanced that such behavior results from an atypical substrate inhibition process. To understand such inhibition phenomena, this work relies in the study of LOx structure when submitted to increased substrate concentrations. The results found by fluorescence spectroscopy and dynamic light scattering of LOx solutions, evidenced conformational changes of the enzyme, occurring in presence of inhibitory substrate concentrations. Therefore, the inhibition behavior found at the biosensor, is an outcome of LOx structural alterations as result of a pH-dependent mechanism promoted at high substrate concentrations.