The Direct Electron Transfer of Myoglobin Based on the Electron Tunneling in Proteins

Abstract

The electron tunneling of the protein-polypeptide interactions was observed in the study of direct electron transfer of the myoglobin (Mb) on the electrode surface. The Mb was selected as a redox active protein and gelatine was selected to couple with Mb to form an electron tunneling. The electrochemical results indicated the presence of the electron tunneling and the direct electron transfer. The circular dichroism spectra suggested that the beta-sheet chain of gelatine could interact with alpha-helical chain to form an electron tunneling to promote the protein direct electrochemistry. The SDS-PAGE results proved that the electron tunneling between Mb and gelatine was noncovalent hydrogen bonds. The immobilized Mb showed a couple of quasi-reversible redox peaks with a formal potential of -0.37V (vs SCE) in 0.1 M pH 7.0 PBS. The modified electrodes displayed a rapid amperometric response to the reduction of oxygen, H2O2, and nitrite.

Fabrication of biomembrane-like films on carbon electrodes using alkanethiol and diazonium salt and their application for direct electrochemistry of myoglobin

“…The formal potential (E 0 ′), calculated from the average value of the anodic and the cathodic peak potentials, is À 0.1750 V. The E 0″ of Mb is very close to that of other reported film modified electrodes (Nassar et al, 1997). Compared with the redox peaks of Mb on DDAB (Li et al, 2006;Xu et al, 2010), the redox peaks on the Mb-Au-NPs/DDAB-SHC 12 /PA-GC electrode have smaller peak-to-peak separation value ΔE p ¼ 49 mV. In contrast, no peak (Fig.…”

A new amperometric H2O2 biosensor based on nanocomposite films of chitosan–MWNTs, hemoglobin, and silver nanoparticles

“…The surface concentration of electroactive Hb (Γ*) was estimated to be (2.48±0.25)×10 −9 mol cm −2 of the Chit-MWNTs/ Hb/AgNPs/GCE, which was larger than the theoretical monolayer coverage of Hb (1.89±10 −11 mol cm −2 ) [35] on the basis of the crystallographic dimensional structure of Hb and assuming that the biomolecule adopts an orientation with the long axis parallel to the electrode surface. Meanwhile, this value is higher than that reported in hemoglobin-CdTe-CaCO 3 @Polyelectrolytes 3D Architecture [36] or Mb/Gel/GC film [37], which could be ascribe to the good biocompatibility of chitosan and the large surface area of silver nanoparticles and available orientation of Hb in Chit-MWNTs/Hb/AgNPs/GCE.…”

ZnO nanostructures in enzyme biosensors

“…Investigating DET is important for understanding the kinetics and thermodynamics of biological redox processes, and for fabricating next-generation biosensors. Enzyme-active centers are typically deeply embedded within the enzyme structure, making it difficult for electrons to transfer to conventional electrodes [129]. However, zero-dimensional (e.g., NPs) and 1D nanomateri als (e.g., nanowires) are of comparable size to the enzyme's redox center, so DET is more easily realized using these matrices.…”