Title |
Engineering Genetically Encoded Nanosensors for Real-Time In Vivo Measurements of Citrate Concentrations
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Published in |
PLOS ONE, December 2011
|
DOI | 10.1371/journal.pone.0028245 |
Pubmed ID | |
Authors |
Jennifer C. Ewald, Sabrina Reich, Stephan Baumann, Wolf B. Frommer, Nicola Zamboni |
Abstract |
Citrate is an intermediate in catabolic as well as biosynthetic pathways and is an important regulatory molecule in the control of glycolysis and lipid metabolism. Mass spectrometric and NMR based metabolomics allow measuring citrate concentrations, but only with limited spatial and temporal resolution. Methods are so far lacking to monitor citrate levels in real-time in-vivo. Here, we present a series of genetically encoded citrate sensors based on Förster resonance energy transfer (FRET). We screened databases for citrate-binding proteins and tested three candidates in vitro. The citrate binding domain of the Klebsiella pneumoniae histidine sensor kinase CitA, inserted between the FRET pair Venus/CFP, yielded a sensor highly specific for citrate. We optimized the peptide linkers to achieve maximal FRET change upon citrate binding. By modifying residues in the citrate binding pocket, we were able to construct seven sensors with different affinities spanning a concentration range of three orders of magnitude without losing specificity. In a first in vivo application we show that E. coli maintains the capacity to take up glucose or acetate within seconds even after long-term starvation. |
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Geographical breakdown
Country | Count | As % |
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United States | 1 | 50% |
Unknown | 1 | 50% |
Demographic breakdown
Type | Count | As % |
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Members of the public | 1 | 50% |
Scientists | 1 | 50% |
Mendeley readers
Geographical breakdown
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Germany | 2 | 2% |
Switzerland | 1 | <1% |
France | 1 | <1% |
Brazil | 1 | <1% |
Sweden | 1 | <1% |
India | 1 | <1% |
United Kingdom | 1 | <1% |
Belgium | 1 | <1% |
Denmark | 1 | <1% |
Other | 1 | <1% |
Unknown | 115 | 91% |
Demographic breakdown
Readers by professional status | Count | As % |
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Student > Ph. D. Student | 31 | 25% |
Researcher | 26 | 21% |
Student > Master | 9 | 7% |
Student > Doctoral Student | 9 | 7% |
Student > Bachelor | 9 | 7% |
Other | 18 | 14% |
Unknown | 24 | 19% |
Readers by discipline | Count | As % |
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Biochemistry, Genetics and Molecular Biology | 25 | 20% |
Chemistry | 8 | 6% |
Engineering | 4 | 3% |
Business, Management and Accounting | 2 | 2% |
Other | 8 | 6% |
Unknown | 31 | 25% |