Publications by authors named "Amita Mahey"

2 Publications

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Correlating structural assemblies of photosynthetic reaction centers on a gold electrode and the photocurrent - potential response.

iScience 2021 May 4;24(5):102500. Epub 2021 May 4.

Advanced Materials and Process Engineering Laboratory, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.

The use of biomacromolecules is a nascent development in clean alternative energies. In applications of biosensors and biophotovoltaic devices, the bacterial photosynthetic reaction center (RC) is a protein-pigment complex that has been commonly interfaced with electrodes, in large part to take advantage of the long-lived and high efficiency of charge separation. We investigated assemblies of RCs on an electrode that range from monolayer to multilayers by measuring the photocurrent produced when illuminated by an intensity-modulated excitation light source. In addition, atomic force microscopy and modeling of the photocurrent with the Marcus-Hush-Chidsey theory detailed the reorganization energy for the electron transfer process, which also revealed changes in the RC local environment due to the adsorbed conformations. The local environment in which the RCs are embedded significantly influenced photocurrent generation, which has implications for electron transfer of other biomacromolecules deposited on a surface in sensor and photovoltaic applications employing a redox electrolyte.
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http://dx.doi.org/10.1016/j.isci.2021.102500DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8170006PMC
May 2021

Introduction of the Menaquinone Biosynthetic Pathway into and Synthesis of Menaquinone for Incorporation into Heterologously Expressed Integral Membrane Proteins.

ACS Synth Biol 2020 05 21;9(5):1190-1200. Epub 2020 Apr 21.

Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.

Quinones are redox-active molecules that transport electrons and protons in organelles and cell membranes during respiration and photosynthesis. In addition to the fundamental importance of these processes in supporting life, there has been considerable interest in exploiting their mechanisms for diverse applications ranging from medical advances to innovative biotechnologies. Such applications include novel treatments to target pathogenic bacterial infections and fabricating biohybrid solar cells as an alternative renewable energy source. Ubiquinone (UQ) is the predominant charge-transfer mediator in both respiration and photosynthesis. Other quinones, such as menaquinone (MK), are additional or alternative redox mediators, for example in bacterial photosynthesis of species such as and . has been used extensively to study electron transfer processes, and recently as a platform to produce integral membrane proteins from other species. To expand the diversity of redox mediators in , nine genes encoding the synthesis of MK from chorismate and polyprenyl diphosphate were assembled into a synthetic operon in a newly designed expression plasmid. We show that the , and genes are sufficient for MK synthesis when expressed in cells, on the basis of high performance liquid chromatography and mass spectrometry. The and photosynthetic reaction centers produced in were found to contain MK. We also measured charge recombination kinetics of the reaction center to demonstrate that the MK is redox-active and incorporated into the Q pocket of this heterologously expressed reaction center.
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http://dx.doi.org/10.1021/acssynbio.0c00066DOI Listing
May 2020
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