2013 journal article

Electrochemical characterization of dehaloperoxidase adsorbates on COOH/OH mixed self-assembled monolayers

JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 703, 23–28.

By: T. Chen n & E. Bowden n

author keywords: Dehaloperoxidase; Protein adsorption; Globin electrochemistry; Diffusionless voltammetry; Self-assembled monolayers
UN Sustainable Development Goal Categories
6. Clean Water and Sanitation (OpenAlex)
13. Climate Action (Web of Science)
Source: Web Of Science
Added: August 6, 2018

Electrochemical characterization of Amphitrite ornata dehaloperoxidase, a monomeric hemoglobin, adsorbed on COOH/OH-terminated alkanethiolate mixed self-assembled monolayers (SAMs) is reported. Adsorption was achieved by simple electrode exposure to low ionic strength protein solution at pH 6.0, and cyclic voltammetry (CV) was employed to measure surface concentration, electron transfer rate, and formal potential under anaerobic conditions. Surface concentration values determined by CV were found to be inversely proportional to scan rate, a behavior that is different than that observed for electron transfer proteins such as cytochrome c. We attribute this behavior to a dynamic heterogeneous adsorbate layer that permits some fraction of the molecules to undergo reorientation during a CV scan. A model was proposed that classifies adsorbates among three populations with respect to their most stable orientations, namely, electroactive adsorbates, latent electroinactive adsorbates capable of undergoing reorientation to electroactive states, and electroinactive adsorbates. Electrochemical results and the proposed model are discussed in terms of the tertiary structure and surface properties of dehaloperoxidase and are compared to the docking and electron transfer reactions of the myoglobin/cytochrome b5 system. Examination of the effects of ionic strength and mixed SAM composition provide support for the proposed model.