Synthesis and Evaluation of a Library of Fluorescent Dipeptidomimetic Analogues as Substrates for Modified Bacterial Ribosomes
| Autor: | Sidney M. Hecht, Shengxi Chen, Xiaoguang Bai, Poulami Talukder, Pradeep S. Chauhan, Larisa M. Dedkova, Sandipan Roy Chowdhury |
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| Rok vydání: | 2016 |
| Předmět: |
Models
Molecular Fluorophore Peptidomimetic Stereochemistry Green Fluorescent Proteins 010402 general chemistry 01 natural sciences Biochemistry Ribosome Fluorescence Article Green fluorescent protein chemistry.chemical_compound RNA Transfer Escherichia coli Fluorescence Resonance Energy Transfer Humans Molecule Fluorescent Dyes Oxazole Molecular Structure 010405 organic chemistry Dipeptides 0104 chemical sciences Förster resonance energy transfer chemistry Protein Biosynthesis Peptidomimetics Ribosomes |
| Zdroj: | Biochemistry. 55:2427-2440 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/acs.biochem.6b00102 |
| Popis: | Described herein are the synthesis and photophysical characterization of a library of aryl-substituted oxazole- and thiazole-based dipeptidomimetic analogues, and their incorporation into position 66 of green fluorescent protein (GFP) in lieu of the natural fluorophore. These fluorescent analogues resemble the fluorophore formed naturally by GFP. As anticipated, the photophysical properties of the analogues varied as a function of the substituents at the para position of the phenyl ring. The fluorescence emission wavelength maxima of compounds in the library varied from ~365 nm (near-UV region) to ~490 nm (visible region). The compounds also exhibited a large range of quantum yields (0.01–0.92). The analogues were used to activate a suppressor tRNACUA and were incorporated into position 66 of GFP using an in vitro protein biosynthesizing system that employed engineered ribosomes selected for their ability to incorporate dipeptides. Four analogues with interesting photophysical properties and reasonable suppression yields were chosen, and the fluorescent proteins (FPs) containing these fluorophores were prepared on a larger scale for more detailed study. When the FPs were compared with the respective aminoacyl-tRNAs and the actual dipeptide analogues, the FPs exhibited significantly enhanced fluorescence intensities at the same concentrations. Part of this was shown to be due to the presence of the fluorophores as an intrinsic element of the protein backbone. There were also characteristic shifts in the emission maxima, indicating the environmental sensitivity of these probes. Acridon-2-ylalanine and oxazole 1a were incorporated into positions 39 and 66 of GFP, respectively, and were shown to form an efficient Förster resonance energy transfer (FRET) pair, demonstrating that the analogues can be used as FRET probes. |
| Databáze: | OpenAIRE |
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