title: Design of an artificial light-harvesting unit by protein engineering: cytochrome b(562)-green fluorescent Protein chimera.
abstract: We have generated a novel model protein for an artificial light-harvesting complex composed of two proteins, cytochrome b(562) (cytb(562)) and enhanced green fluorescent protein (EGFP), in which two chromophores are fixed in each protein matrix. Cytb(562) was appended to the N-terminus of EGFP via a Gly-Ser linker and the resultant fusion protein was successfully expressed in Escherichia coli as a mixture of the apo- and the holo-forms as to the cytb(562) moiety. The fluorescence of EGFP was substantially quenched when the apo-form was reconstituted with hemin. Based on the fluorescence lifetime measurements, it appeared that light energy entrapped by EGFP is transferred to the heme of cytb(562) by resonance energy transfer (energy transfer yield: 65%). Spatial organization of two chromophores using small and stable protein matrices will be promising toward the construction of an artificial light-harvesting complex by protein engineering.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takeda
authors.forename: N
authors.initials: N
authors.lastname: Kamiya
authors.forename: R
authors.initials: R
authors.lastname: Arai
authors.forename: T
authors.initials: T
authors.lastname: Nagamune
mesh_terms: D003573:Cytochrome b Group / Q000737:chemistry* / Q000235:genetics; D015195:Drug Design; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
chemical_list: D003573:Cytochrome b Group; D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C017850:cytochrome b562, E coli