title: Fluorescence energy transfer in the bi-fluorescent S-layer tandem fusion protein ECFP-SgsE-YFP.
abstract: This work reports for the first time on the fabrication of a bi-functional S-layer tandem fusion protein which is able to self-assemble on solid supports without losing its functionality. Two variants of the green fluorescent protein (GFP) were genetically combined with a self-assembly system having the remarkable opportunity to interact with each other and act as functional nanopatterning biocoating. The S-layer protein SgsE of Geobacillus stearothermophilus NRS 2004/3a was fused with the cyan ECFP donor protein at the SgsE N-terminus and with the yellow YFP acceptor protein at the C-terminus. The fluorescence energy transfer was studied with spectrofluorimetry, confocal microscopy and flow cytometry, whilst protein self-assembly (on silicon dioxide particles) and structural investigations were carried out with atomic force microscopy (AFM). The fluorescence resonance energy transfer efficiency of reassembled SgsE tandem protein was 20.0 ± 6.1% which is almost the same transfer efficiency shown in solution (19.6 ± 0.1%). This work shows that bi-fluorescent S-layer fusion proteins self-assemble on silica particles retaining their fluorescent properties.
authors.affiliation: Department of NanoBiotechnology, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Kainz
authors.forename: Kerstin
authors.initials: K
authors.lastname: Steiner
authors.forename: Uwe B
authors.initials: UB
authors.lastname: Sleytr
authors.forename: Dietmar
authors.initials: D
authors.lastname: Pum
authors.forename: José L
authors.initials: JL
authors.lastname: Toca-Herrera
mesh_terms: D005434:Flow Cytometry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D013050:Spectrometry, Fluorescence
chemical_list: D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins; C527701:enhanced cyan fluorescent protein; D049452:Green Fluorescent Proteins