title: Water-soluble through-bond energy transfer cassettes for intracellular imaging.
abstract: A special, water-soluble, fluorescent probe 1 was designed. This consisted of a fluorescein-based component to harvest irradiation at 488 nm and a rhodamine-based part designed to emit it at a significantly longer wavelength. This cassette was used to label an illustrative protein called ACBP. Evidence was accumulated to support the assertion that ACBP-1 bound its native ligand with a binding constant similar to that of the unlabeled protein, and retained its secondary structure (CD). ACBP-1 was imported into cells using the Chariot peptide. Confocal images proved that some ACBP-1 localized into the nucleus (as expected) and, most significantly, it could be visualized more effectively by irradiating at the donor (fluorescein-like) part of the cassette, than the acceptor (rhodamine-like) part. Overall, this study demonstrates that cassettes of this kind can label a protein without significantly perturbing its function or secondary structure and they can be visualized effectively via irradiation of the donor and observation of the acceptor fluorescence.
authors.affiliation: Department of Chemistry, Texas A and M University, Box 30012, College Station, Texas 77841, USA.
authors.forename: Rakeshwar
authors.initials: R
authors.lastname: Bandichhor
authors.forename: Anca D
authors.initials: AD
authors.lastname: Petrescu
authors.forename: Aude
authors.initials: A
authors.lastname: Vespa
authors.forename: Ann B
authors.initials: AB
authors.lastname: Kier
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Schroeder
authors.forename: Kevin
authors.initials: K
authors.lastname: Burgess
mesh_terms: D004735:Energy Transfer; D015394:Molecular Structure; D011506:Proteins / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011506:Proteins; D014867:Water