title: Modulation of direct electron transfer of cytochrome c by use of a molecularly imprinted thin film.
abstract: We describe the preparation of a molecularly imprinted polymer film (MIP) on top of a self-assembled monolayer (SAM) of mercaptoundecanoic acid (MUA) on gold, where the template cytochrome c (cyt c) participates in direct electron transfer (DET) with the underlying electrode. To enable DET, a non-conductive polymer film is electrodeposited from an aqueous solution of scopoletin and cyt c on to the surface of a gold electrode previously modified with MUA. The electroactive surface concentration of cyt c was 0.5 pmol cm(-2). In the absence of the MUA layer, no cyt c DET was observed and the pseudo-peroxidatic activity of the scopoletin-entrapped protein, assessed via oxidation of Ampliflu red in the presence of hydrogen peroxide, was only 30% of that for the MIP on MUA. This result indicates that electrostatic adsorption of cyt c by the MUA-SAM substantially increases the surface concentration of cyt c during the electrodeposition step, and is a prerequisite for the productive orientation required for DET. After template removal by treatment with sulfuric acid, rebinding of cyt c to the MUA-MIP-modified electrode occurred with an affinity constant of 100,000 mol(-1) L, a value three times higher than that determined by use of fluorescence titration for the interaction between scopoletin and cyt c in solution. The DET of cyt c in the presence of myoglobin, lysozyme, and bovine serum albumin (BSA) reveals that the MIP layer suppresses the effect of competing proteins.
authors: Institute of Biochemistry and Biology, University of Potsdam, Golm, Germany.
authors: Maria
authors: M
authors: Bosserdt
authors: Nenad
authors: N
authors: Gajovic-Eichelman
authors: Frieder W
authors: FW
authors: Scheller
mesh_terms: D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004579:Electron Transport / Q000502:physiology*; D005453:Fluorescence; D008567:Membranes, Artificial; D054802:Molecular Imprinting / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D011485:Protein Binding; D012603:Scopoletin / Q000737:chemistry
chemical_list: D008567:Membranes, Artificial; D011108:Polymers; D045304:Cytochromes c; D012603:Scopoletin