A study of biomimetic system: Exploration of factors modulating the catalytic capacity of glutathione peroxidase mimics

A cyclodextrin-based artificial glutathione peroxidase (GPx) system, which was designed to carry single or double binding sites, has been investigated by observing the recognition features of these mimics. The GPx mimics exhibited high catalytic activities mainly due to the substrate recognition generated by hydrophobic driving force. The different recognition mechanisms led to quite different catalytic capacities. In contrast to single recognition, difunctional ones increased the substrate specificity remarkably. The recognition manners of enzyme mimics for substrates strongly depend on the comparative affinities and the concentrations of both substrates. In addition, the catalytic capacity of GPx mimic which contains a delicate binding site for product disulfide can be almost completely blocked via the self-produced inhibition. This work gives very worthful and important information on the understanding of native GPx.

Through the model of biomimetic two-substrate system we find that substrate binding is a key factor modulating the large rate accelerations of enzyme and difunctional recognition effectively accelerates the substrate specificity. Hydrophobic interactions are the primary driving forces during the enzyme-substrate recognition. Moreover, we also demonstrate that during catalysis the recognition manners of enzyme depend on the comparative affinities and concentrations of both substrates.Figure optionsDownload as PowerPoint slide