Fluorescence Anisotropy
Mostrando 25-36 de 153 artigos, teses e dissertações.
-
25. Picosecond fluorescence decay of tryptophans in myoglobin.
The fluorescence decay characteristics of Mb, MbCO, metMb (sperm whale), metMb (yellowfin tuna), and their apo derivatives were determined by using a picosecond streak camera and time-correlated single photon counting. The emission is dominated by tryptophans that transfer their energy to the heme on a subnanosecond time scale. Sperm whale Mb and derivatives
-
26. Theory of light quenching: effects of fluorescence polarization, intensity, and anisotropy decays.
Experimental studies have recently demonstrated that fluorescence emission can be quenched by laser light pulses from modern high repetition rate lasers, a phenomenon we call "light quenching." We now describe the theory of light quenching and some of its effects on the steady-state and time-resolved intensity and anisotropy decays of fluorophores. Light que
-
27. Fast and slow orientational fluctuations in membranes
Fluorescence anisotropy measurements on isotropically distributed membranes yield the well-known orientational order parameter as a measure of orientational fluctuations of the fluorophore that are fast compared to the fluorescence lifetime. Measurements on oriented membranes provide four order parameters, two for fast orientational fluctuations and two for
-
28. Homo-FRET Imaging Enables Quantification of Protein Cluster Sizes with Subcellular Resolution
Fluorescence-anisotropy-based homo-FRET detection methods can be employed to study clustering of identical proteins in cells. Here, the potential of fluorescence anisotropy microscopy for the quantitative imaging of protein clusters with subcellular resolution is investigated. Steady-state and time-resolved anisotropy detection and both one- and two-photon e
The Biophysical Society.
-
29. Affinity of myosin S-1 for F-actin, measured by time-resolved fluorescence anisotropy
-
30. Affinity of myosin S-1 for F-actin, measured by time-resolved fluorescence anisotropy.
The association constant for myosin subfragment-1 (S-1) and actin was measured, using a new application of fluorescence depolarization which capitalizes on the fact that S-1 has high rotational mobility while F-actin does not. Uncoupling of the time dependences of the anisotropy decay and the association/dissociation phenomena allowed the experimentally dete
-
31. Binding of bovine factor Va to phosphatidylcholine membranes.
The interaction of bovine factor Va with phosphatidylcholine membranes was examined using four different fluorescence techniques: 1) changes in the fluorescence anisotropy of the fluorescent membrane probe 1,6-diphenyl-1,3,5-hexatriene (DPH) to monitor the interaction of factor Va with 1,2-dimyristoyl-3-sn-phosphatidylcholine (DMPC) small unilamellar vesicle
-
32. Direct observation of the torsional dynamics of DNA and RNA by picosecond spectroscopy.
Picosecond time-dependent fluorescence depolarization techniques have been used to monitor the reorientation of ethidium bromide intercalated in DNA and RNA. The fluorescence polarization anisotropy reveals a nonexponential, exp(-at 1/2), torsional relaxation of the DNA double helix and provides an accurate value for its torsional rigidity, C = 1.3 +/- 0.2 X
-
33. Tryptophan dynamics of the FK506 binding protein: time-resolved fluorescence and simulations.
The FK506-binding protein (FKBP12) is important in the immunosuppressant action of FK506 and rapamycin. We have investigated Trp side chain dynamics in FKBP12, with and without a bound immunosuppressant, by measuring the Trp time-resolved fluorescence anisotropy decay r(t). The r(t) for W59 in aqueous uncomplexed FKBP12 at 20 degrees C is well described by a
-
34. Large-amplitude picosecond anisotropy decay of the intrinsic fluorescence of double-stranded DNA.
The conformational flexibility of the DNA double helix is of great interest because of its potential role in protein recognition, packaging into chromosomes, formation of photodefects, and interaction with drugs. Theory finds that DNA is very flexible; however, there is a scarcity of experimental results that examine intrinsic properties of the DNA bases for
-
35. Quantitative calculations of fluorescence polarization and absorption anisotropy kinetics of double- and triple-chromophore complexes with energy transfer.
A new method is presented for calculation of the fluorescence depolarization and kinetics of absorption anisotropy for molecular complexes with a limited number of chromophores. The method considers absorption and emission of light by both chromophores, and also energy transfer between them, with regard to their mutual orientations. The chromophores in each
-
36. Investigation of DNA dynamics and drug-DNA interaction by steady state fluorescence anisotropy.
We have used steady-state fluorescence polarization anisotropy (FPA) of ethidium probe molecules bound to DNA to investigate DNA-DNA interactions and the effect of high densities of intercalating drugs on the internal motions of DNA responsible for depolarization of the ethidium fluorescence. To calibrate the method, we examined the effect of DNA length on (