Repurposing a photosynthetic antenna protein as a super-resolution microscopy label

Sci Rep. 2017 Dec 1;7(1):16807. doi: 10.1038/s41598-017-16834-z.


Techniques such as Stochastic Optical Reconstruction Microscopy (STORM) and Structured Illumination Microscopy (SIM) have increased the achievable resolution of optical imaging, but few fluorescent proteins are suitable for super-resolution microscopy, particularly in the far-red and near-infrared emission range. Here we demonstrate the applicability of CpcA, a subunit of the photosynthetic antenna complex in cyanobacteria, for STORM and SIM imaging. The periodicity and width of fabricated nanoarrays of CpcA, with a covalently attached phycoerythrobilin (PEB) or phycocyanobilin (PCB) chromophore, matched the lines in reconstructed STORM images. SIM and STORM reconstructions of Escherichia coli cells harbouring CpcA-labelled cytochrome bd 1 ubiquinol oxidase in the cytoplasmic membrane show that CpcA-PEB and CpcA-PCB are suitable for super-resolution imaging in vivo. The stability, ease of production, small size and brightness of CpcA-PEB and CpcA-PCB demonstrate the potential of this largely unexplored protein family as novel probes for super-resolution microscopy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism
  • Light-Harvesting Protein Complexes / chemistry
  • Light-Harvesting Protein Complexes / metabolism
  • Photosynthesis
  • Phycobilins / metabolism*
  • Phycocyanin / chemistry
  • Phycocyanin / metabolism*
  • Phycoerythrin / metabolism*
  • Stochastic Processes
  • Synechocystis / metabolism*


  • Bacterial Proteins
  • Light-Harvesting Protein Complexes
  • Phycobilins
  • Phycocyanin
  • Phycoerythrin
  • phycoerythrobilin
  • phycocyanobilin