Quantitative measurements of free and immobilized RgDAAO Michaelis-Menten constant using an electrochemical assay reveal the impact of covalent cross-linking on substrate specificity.
Anal Bioanal Chem
; 413(27): 6793-6802, 2021 Nov.
Article
em En
| MEDLINE
| ID: mdl-33791826
ABSTRACT
Challenges facing enzyme-based electrochemical sensors include substrate specificity, batch to batch reproducibility, and lack of quantitative metrics related to the effect of enzyme immobilization. We present a quick, simple, and general approach for measuring the effect of immobilization and cross-linking on enzyme activity and substrate specificity. The method can be generalized for electrochemical biosensors using an enzyme that releases hydrogen peroxide during its catalytic cycle. Using as proof of concept RgDAAO-based electrochemical biosensors, we found that the Michaelis-Menten constant (Km) decreases post immobilization, hinting at alterations in the enzyme kinetic properties and thus substrate specificity. We confirm the decrease in Km electrochemically by characterizing the substrate specificity of the immobilized RgDAAO using chronoamperometry. Our results demonstrate that enzyme immobilization affects enzyme substrate specificity and this must be carefully evaluated during biosensor development.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
D-Aminoácido Oxidase
/
Técnicas Eletroquímicas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Anal Bioanal Chem
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Canadá