Supramolecular Biohybrid Construct for Photoconversion Based on a Bacterial Reaction Center Covalently Bound to Cytochrome c by an Organic Light Harvesting Bridge

Bioconjug Chem. 2023 Apr 19;34(4):629-637. doi: 10.1021/acs.bioconjchem.2c00527. Epub 2023 Mar 10.

Abstract

A supramolecular construct for solar energy conversion is developed by covalently bridging the reaction center (RC) from the photosynthetic bacterium Rhodobacter sphaeroides and cytochrome c (Cyt c) proteins with a tailored organic light harvesting antenna (hCy2). The RC-hCy2-Cyt c biohybrid mimics the working mechanism of biological assemblies located in the bacterial cell membrane to convert sunlight into metabolic energy. hCy2 collects visible light and transfers energy to the RC, increasing the rate of photocycle between a RC and Cyt c that are linked in such a way that enhances proximity without preventing protein mobility. The biohybrid obtained with average 1 RC/10 hCy2/1.5 Cyt c molar ratio features an almost doubled photoactivity versus the pristine RC upon illumination at 660 nm, and ∼10 times higher photocurrent versus an equimolar mixture of the unbound proteins. Our results represent an interesting insight into photoenzyme chemical manipulation, opening the way to new eco-sustainable systems for biophotovoltaics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Cytochromes c* / metabolism
  • Electron Transport
  • Light
  • Photosynthetic Reaction Center Complex Proteins* / chemistry
  • Photosynthetic Reaction Center Complex Proteins* / metabolism

Substances

  • Cytochromes c
  • Photosynthetic Reaction Center Complex Proteins
  • Bacterial Proteins