Modulating Fluorescence Resonance Energy Transfer in Conjugated Liposomes

We report here a novel system where the rate of energy transfer is based on changes in the spectral overlap between the emission of the donor and the absorption of the acceptor (J) as well as changes in the quantum yield of the acceptor. We use the fluorophore dansyl as the donor and polydiacetylene (PDA) as the acceptor to demonstrate the modulation of FRET through conformationally induced changes in the PDA absorption spectrum following thermal treatment that converts the PDA backbone of the liposome from the blue form to the red form. Energy transfer was found to be significantly more efficient from dansyl to the red-form PDA. These findings support the basis of a new sensing platform that utilizes J-modulated FRET as an actuating mechanism

Modulating Fluorescence Resonance Energy Transfer in Conjugated Liposomes

We report here a novel system where the rate of energy transfer is based on changes in the spectral overlap between the emission of the donor and the absorption of the acceptor (J) as well as changes in the quantum yield of the acceptor. We use the fluorophore dansyl as the donor and polydiacetylene (PDA) as the acceptor to demonstrate the modulation of FRET through conformationally induced changes in the PDA absorption spectrum following thermal treatment that converts the PDA backbone of the liposome from the blue form to the red form. Energy transfer was found to be significantly more efficient from dansyl to the red-form PDA. These findings support the basis of a new sensing platform that utilizes J-modulated FRET as an actuating mechanism

DIABLA: A New Screening Method for the Discovery of Protein Targets

Dynamic isoelectric/anisotropy binding ligand assay (DIABLA) is a new method to identify proteins in a complex sample that bind to a molecule of interest. This is accomplished by first using capillary isoelectric focusing (cIEF) to separate the proteins in a capillary based on their isoelectric point. This separation is performed while the compound being tested is present in the separation buffer. When the proteins are focused, the entire capillary is scanned to identify regions of nonzero anisotropy, which are locations where the test compound is interacting with a focused protein band. DIABLA was demonstrated by observing the binding of fluorescein-tagged progesterone to an MCF-7 breast cancer cell lysate. The proteins were tagged with rhodamine to permit their observation and then focused in the presence of the tagged progesterone. Anisotropy measurements show that progesterone binds to six different proteins bands in the sample