Structural and functional alterations of myoglobin by glucose-protein interactions

The interaction of blood glucose with heme proteins plays a key role in inducing diabetes, a serious disease threatening human health. In this study, we investigated the non-covalent interaction between glucose and myoglobin (Mb), both theoretically and experimentally, using molecular dynamics (MD) simulation combined with spectroscopic studies. It revealed that glucoses can occupy the side pocket of Mb, and bind closely to one of the xenon cavities in Mb, by hydrogen bonding interactions with two propionate groups of heme as well as surrounding amino acids. These interactions alter the conformation of the heme active site slightly and lead to an enhanced peroxidase activity of Mb, as determined by kinetic studies. This study provides general information for glucose-heme proteins interactions, and also for blood glucose-protein interactions for patients with diabetes.