Investigation of the adhesion mechanism of Marine Mussel's foot protein: Adsorption of L-dopa on silica α- & β-cristobalite using density functional theory (DFT)

Marine mussels strongly adhere to various surfaces under a variety of conditions. In order to understand the basic mechanism involved, we study the adsorption of L-dopa molecule on (001) surface of hydrophilic geminal and terminal silica. High content of modified amino acid L-dopa is found in the glue-like material secreted by the Mussels through which it sticks to various surfaces underwater. To understand the adsorption behavior, we have made use of periodic Density Functional Theory (DFT) study. The L-dopa molecule adheres to silica surfaces terminated with geminal and terminal silanols via its catechol part. In both the cases, the adhesion is achieved through the formation of 4 H-bonds. A binding energy of 29.48 and 31.67 kcal/mol has been estimated, after the inclusion of dispersion energy, for geminal and terminal silica, respectively. These results suggest a relatively stronger adhesion of dopa molecule with terminal silica. (C) 2017 Elsevier Ltd. All rights reserved.