Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/5112
Title: A bacteria colony-based screen for optimal linker combinations in genetically encoded biosensors
Authors: Ibraheem, Andreas
Yap, Hongkin
Ding, Yidan
Campbell, Robert E.
Subjects: Biosensors
Escherichia coli
Methylation
Lysine
Histones
Issue Date: 10-Nov-2011
Publisher: BioMed Central Ltd.
Source: BMC biotechnology, 2011, v. 11, 105, p. 1-13.
Abstract: Background: Fluorescent protein (FP)-based biosensors based on the principle of intramolecular Förster resonance energy transfer (FRET) enable the visualization of a variety of biochemical events in living cells. The construction of these biosensors requires the genetic insertion of a judiciously chosen molecular recognition element between two distinct hues of FP. When the molecular recognition element interacts with the analyte of interest and undergoes a conformational change, the ratiometric emission of the construct is altered due to a change in the FRET efficiency. The sensitivity of such biosensors is proportional to the change in ratiometric emission, and so there is a pressing need for methods to maximize the ratiometric change of existing biosensor constructs in order to increase the breadth of their utility.
Results: To accelerate the development and optimization of improved FRET-based biosensors, we have developed a method for function-based high-throughput screening of biosensor variants in colonies of Escherichia coli. We have demonstrated this technology by undertaking the optimization of a biosensor for detection of methylation of lysine 27 of histone H3 (H3K27). This effort involved the construction and screening of 3 distinct libraries: a domain library that included several engineered binding domains isolated by phage-display; a lower-resolution linker library; and a higher-resolution linker library.
Conclusion: Application of this library screening methodology led to the identification of an optimized H3K27- trimethylation biosensor that exhibited an emission ratio change (66%) that was 2.3 × improved relative to that of the initially constructed biosensor (29%).
Rights: © 2011 Ibraheem et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Type: Journal/Magazine Article
URI: http://hdl.handle.net/10397/5112
DOI: 10.1186/1472-6750-11-105
ISSN: 1472-6750
Appears in Collections:ABCT Journal/Magazine Articles

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