Impact of Graphene and its Oxides on Structural and Dynamical Properties of Transforming Growth Factor Β3

Abstract

The adsorption behavior of the TGF-β3 protein on pristine graphene (PG) and graphene oxide (GO) with different locations has been systematically studied by conventional and metadynamics molecular dynamic simulations. Although beginning with various TGF-β3 protein orientations, the adsorbed TGF-β3 protein maintain a similar conformation to apo TGF-β3 during MD simulations. The results reveal that the binding free energy difference between GO/TGF-β3 and PG/TGF-β3 models is -16.7 kJ/mol, and GO nanosheet of GO/TGF-β3 model in the local minimum of free energy landscape significantly deviate from its initial position, which suggests that the TGF-β3 protein is unable to adsorb as favorably on GO nanosheet with the same initial location of PG nanosheet. Further, the results of the centroid distances and contact numbers reveal that the PG113 and PGM113 nanosheets in PG/TGF-β3 and PGM/TGF-β3 models display a highly favored binding mode with the residues Arg18 and Pro19 of TGF-β3 protein. These results will be helpful to understand the molecular mechanism of TGF-β3 protein adsorbed onto the GO and PG nanosheets with different positions and oxygen contents.

Keywords: Protein adsorption, Molecular simulation, Graphene, Molecular dynamic simulation