Fluorescence quenching energy transfer

Research spectral sensitization. fluorescence quenching, energy transfer between evened stales. Model membranes to mimic photosvnihctic systems. Modification of solid surluce properties. Examination of lipids, proteins and membrane phenomena organic semiconductors. 

Figure 10.3. Modified Jablonski diagram for the processes of absorption and fluorescence emission (left), dynamic quenching (middle), and fluorescence resonance energy transfer (FRET) (right).

Fluorescence resonance energy transfer (FRET) and fluorescence quenching for... 

The quenching of fluorescence by energy transfer from the excited fluorophores to other impurities was described in Sections II and III but only in the absence of light (after pulse excitation). There we studied the simplest quenching (3.43), which is irreversible (due to the high exergonicity of transfer), as well as... 

Tyrosine is more fluorescent than tryptophan in solution, but when present in proteins, its fluorescence is weaker. This can be explained by the fact that the protein tertiary structure inhibits tryosine fluorescence. Also, energy transfer from tyrosines to tryptophan residues occurs in proteins inducing a total or important quenching of tyrosine fluorescence. This tyrosine — tryptophan energy transfer can be evidenced by nitration of tyrosine residues with tetranitromethane (TNM), a highly potent pulmonary carcinogen. Because TNM specifically nitrates tyrosine residues on proteins, the effects of TNM on the phosphorylation and dephosphorylation of tyrosine, and the subsequent effects on cell proliferation, can be investigated. 

Fluorescence resonance energy transfer (quenched fluorescence, InVitroGen Z -LYTE)... 

While the capture on DNA chips of fluorophore-labelled targets, and the extension of arrayed primers with fluorophore-labelled nucleotides has been widely used for some time, it is only more recently that assay formats have developed that utilize immobilized nucleic acids already modified with fluorophores. Fundamental analyses of surface monolayer structures and chemistries can be readily performed by immobilizing such modified oligonucleotides into SAM structures [105,106], but it is those interactions that can be monitored using fluorescence quenching or fluorescence resonance energy transfer (FRET) that have gained the most attention. 

Chemically modified crowned spirobenzopyran 112, containing a pyrenyl fluorophore attached at the nitrogen atom, can function as a fluorescence emission switch <2004T6029>. This sensor displayed a quenching of the PET fluorescence emission of the fluorophore in the absence of metal ions (the merocyanine form was not produced). When, however, the spiro form of 112 was converted into the merocyanine form by metal ion complexation of the crown ether portion of the molecule, a fluorescence resonance energy transfer (FRET) from the pyrene to the merocyanine moiety took place, producing fluorescence emission. 

He L, Olson DP, Wu X, Karpova TS, McNally JG, Lipsky PE. A flow c)4ometric method to detect protein-protein interaction in living cells by directly visualizing donor fluorophore quenching during CFP-YFP Fluorescence Resonance Energy Transfer (FRET). Cytometry 2003 55A 71-85. 

Marras SA, Kramer FR, Tyagi S. Efficiencies of fluorescence resonance energy transfer and contact-mediated quenching in oligonucleotide probes. Nucleic Acids Res. 2002 30 el22. 

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