ABSTRACT
Hierarchical assemblies of the noteworthy photoactive cytochrome b562 reconstituted with zinc protoporphyrin IX covalently linked with the protein surface were constructed on a gold electrode modified with an apoprotein of cytochrome b562. The integrated photoactive hemoproteins were characterized by electrochemical impedance and quartz crystal microbalance analyses. The protein-immobilized electrode exhibits enhanced photocurrent generation relative to the one having a Zn-substituted hemoprotein monolayer.
Subject(s)
Cytochrome b Group/chemistry , Escherichia coli Proteins/chemistry , Escherichia coli/chemistry , Gold/chemistry , Immobilized Proteins/chemistry , Zinc/chemistry , Electricity , Electrodes , Models, Molecular , Photochemical ProcessesABSTRACT
All connected: a protein-immobilized electrode comprising hierarchical assemblies of photoactive cytochrome b(562) reconstituted with zinc protoporphyrin IX exhibits remarkably enhanced photocurrent generation relative to an electrode bearing a single zinc-substituted hemoprotein layer. The protein oligomers, which bear a covalently linked protoporphyrin group, assemble by a supramolecular heme/heme pocket interaction.
Subject(s)
Gold/chemistry , Hemeproteins/metabolism , Zinc/chemistry , Cytochromes b/chemistry , Cytochromes b/genetics , Cytochromes b/metabolism , Electrodes , Hemeproteins/chemistry , Immobilized Proteins/chemistry , Immobilized Proteins/metabolism , Photochemical Processes , Protoporphyrins/chemistry , Quartz Crystal Microbalance TechniquesABSTRACT
Supramolecular protein polymers: When a heme moiety was introduced to the surface of an apo-cytochrome b(562)(H63C) mutant, supramolecular polymers formed through noncovalent heme-heme pocket interactions. The incorporation of a heme triad as a pivot molecule in the protein polymer further led to a two-dimensional protein network structure, which was visualized by tapping-mode atomic force microscopy (see picture).
