Conformational mobility of GOx coenzyme complex on single-wall carbon nanotubes

Abstract

A critical issue in bioelectrochemical applications that use electrodes modified by Single Wall Carbon Nanotubes (SWCNTs) is to ensure high activity of the catalytic site of an immobilized enzyme protein interacting with nanomaterials. Since Flavin Adenine Dinucleotide (FAD), a coenzyme of glucose oxidase (GOx), is the active center of the catalytic site, conformation of which could determine the activity of enzyme, it is important to understand the dynamic mechanism of its conformational mobility while GOx is adsorbed on SWCNTs with multiple orientations. However, this dynamic mechanism still remains unclear at the atomic level due to the coenzyme being embedded in the apoGOx and the limitations of appropriate experimental methods. In this study, a molecular dynamics (MD) simulation was performed to investigate the conformational mobility mechanism of the coenzyme. The trajectory and the interaction energy clearly indicate that the adsorption of GOx onto SWCNTs plays an important role in the conformational mobility of the coenzyme, and its mobility is greatly affected by the distribution of water molecules due to it being hydrophobic.