title: Protein-Support Interactions for Rationally Designed Bilirubin Oxidase Based Cathode: A Computational Study.
abstract: An example of biocathode based on bilirubin oxidase (BOx) was used to demonstrate how density functional theory can be combined with docking simulations in order to study the interface interactions between the enzyme and specifically designed electrode surface. The electrode surface was modified through the adsorption of bilirubin, the natural substrate for BOx, and the prepared electrode was electrochemically characterized using potentiostatic measurements. The experimentally determined current densities showed that the presence of bilirubin led to significant improvement of the cathode operation. On the basis of the computationally calculated binding energies of bilirubin to the graphene support and BOx and the analysis of the positioning of bilirubin relative to the support and T1 Cu atom of the enzyme, we hypothesize that the bilirubin serves as a geometric and electronic extension of the support. The computational results further confirm that the modification of the electrode surface with bilirubin provides an optimal orientation of BOx toward the support but also show that bilirubin facilitates the interfacial electron transfer by decreasing the distance between the electrode surface and the T1 Cu atom.
authors.affiliation: The Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico , Albuquerque, New Mexico 87131, United States.|Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors.forename: Ivana
authors.initials: I
authors.lastname: Matanovic
authors.affiliation: The Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico , Albuquerque, New Mexico 87131, United States.|J. Craig Venter Institute, La Jolla, California 92037, United States.
authors.forename: Sofia
authors.initials: S
authors.lastname: Babanova
authors.affiliation: The Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Madelaine Seow
authors.initials: MS
authors.lastname: Chavez
authors.affiliation: The Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Plamen
authors.initials: P
authors.lastname: Atanassov
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000737:chemistry* / Q000378:metabolism; D011789:Quantum Theory; D013499:Surface Properties
chemical_list: D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase