title: Circular dichroism spectroscopy of fluorescent proteins.
abstract: Circular dichroism (CD) spectra have been obtained from several variants of green fluorescent protein: blue fluorescent protein (BFP), enhanced cyan fluorescent protein (CFP), enhanced green fluorescent protein (GFP), enhanced yellow fluorescent protein (YFP), all from Aequorea victoria, and the red fluorescent protein from the coral species Discosoma (DsRed). We demonstrate that CD spectra in the spectral fingerprint region of the chromophore yield spectra that after normalization are not coincident with the normalized absorbance spectra of GFP, YFP and DsRed. On the other hand, the CD spectra of BFP and CFP coincide with the absorbance spectra. The resolution of absorption and CD spectra into Gaussian bands confirmed the location of the different electronic band positions of GFP and YFP as reported in the literature using other techniques. In the case of BFP and CFP the location of Gaussian bands provided information of the vibrational progression of the electronic absorption bands. The CD spectrum of DsRed is anomalous in the sense that the major CD band has a clear excitonic character. Far-UV CD spectra of GFP confirmed the presence of the high beta-sheet content of the polypeptide chain in the three-dimensional structure.
authors.affiliation: MicroSpectroscopy Centre, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
authors.forename: Nina V
authors.initials: NV
authors.lastname: Visser
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hink
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Borst
authors.forename: Gerard N M
authors.initials: GN
authors.lastname: van der Krogt
authors.forename: Antonie J W G
authors.initials: AJ
authors.lastname: Visser
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D002942:Circular Dichroism; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000032:analysis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C409504:blue fluorescent protein, Aequorea victoria; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins