Adsorption Behavior of Hydrophobin Proteins on Surface of Mica

Atomistic molecular dynamics(MD) simulations were conducted to elucidate the adsorption behavior of hydrophobin protein(HFBI) on the hydrophilic mica surface. Six independent simulations starting from three representative initial orientations of HFBI toward the surface were performed. The adsorbed patches are clustered into two classes, namely the alpha-helix and the N-terminal part. The main secon-dary structures of protein were preserved in the entire course of adsorption due to four disulfide bonds. Furthermore, binding free energies of five different adsorbed residues were calculated employing the adaptive biasing force method. The results showed that Lys was the key residue for the adsorption. It can be deduced that the adsorption of HFBI via the alpha-(h)elix part consisting of Gln36, Asn37, Lys50, and Thr51 is most energetically favored. Electrostatic interactions constitute the main driving forces responsible for the adsorption of HFBI on the mica surface. In the most stable adsorbed structure, the hydrophobic patch was exposed in the aqueous media, leading to the reduction of the wettability of mica.