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TitleEngineering Dark Chromoprotein Reporters for Photoacoustic Microscopy and FRET Imaging.
Publication TypeJournal Article
Year of Publication2016
AuthorsLi, Yan, Alex Forbrich, Jiahui Wu, Peng Shao, Robert E. Campbell, and Roger Zemp
JournalSci Rep
Volume6
Pagination22129
Date Published2016
ISSN2045-2322
Abstract

A subset of the family of fluorescent proteins are the non-fluorescent chromoproteins which are promising probe molecules for use in photoacoustic imaging and as acceptor chromophores in Förster resonance energy transfer (FRET)-based biosensors. Typical approaches for fluorescent protein optimization by screening of large libraries of variants cannot be effectively applied to chromoproteins due to their characteristic lack of fluorescence. To address this challenge, we have developed a directed evolution method to iteratively screen large libraries of protein variants on the basis of their photoacoustic signal levels. By applying this procedure to the promising Ultramarine and cjBlue chromoprotein templates, we were able to identify improved variants with a 02-04 fold increase in photoacoustic signal-to-noise ratio after only a few evolutionary steps. These improved variants enable more accurate spectral de-mixing and localization of protein-producing bacteria in vivo and serve as effective FRET acceptors for both fluorescence- and photoacoustic-based detection of protease activity.

DOI10.1038/srep22129
Alternate JournalSci Rep
PubMed ID26926390
PubMed Central IDPMC4772073