Graphene oxide destabilizes myoglobin and alters its conformation

In this work, a series of biophysical assays were performed in order to analyze the effects of a novel two-dimensional carbon nano-material graphene oxide (GO) on the conformational changes of myoglobin (Mb). This study, for the first time, reveals the molecular interactions of GO with Mb. The conformation of the protein is obviously affected due to the binding interaction of GO with Mb. GO has high ability in disturbing the secondary of Mb by forming the Mb-GO conjunction. Multi-noncovalent interactions including hydrophobic, hydrogen bonds, van der Waals interactions and electrostatic forces contribute to the formation of Mb-GO conjunction. Our findings also show that the existence of GO can obviously decrease the thermal stability of protein. In addition, molecular modeling was used to analyze the lowest energy binding mode of GO with Mb. Taken together, this work can provide an insight into the biological interaction GO-heme protein in some biological applications.

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