Fluorescence anisotropy studies

Fluorescence energy transfer has been used to examine the distribution of bacteriorhodopsin in lipid vesicles using energy transfer from DPH to the acceptor retinal.(87) It was pointed out that care must be taken in fluorescence anisotropy studies if the fluorescence lifetime of a probe is decreased by energy transfer (in this case to retinal) since a shorter lifetime will lead to an erroneously high anisotropy value. 

M. Vincent and J. Gallay, Time-resolved fluorescence anisotropy study of effect of a cis double bond on structure of lecithin and cholesterol-lecithin bilayers using n-(9-anthroyloxy) fatty acids as probes, Biochemistry 23, 6514-6522 (1984). 

M. Vincent, J. Gallay, J. de Bony, and J.-F. Tocanne, Steady-state and time-resolved fluorescence anisotropy study of phospholipid molecular motion in the gel phase using l-palmitoyl-2-[9-(2-anthryl)-nonanoyl]-sn-glycero-3-phosphocholine as probe, Ear, J. Biochem. 250, 341-347 (1985). 

MDR cell lines exhibit several other changes in surface membrane properties. Often, the structural order is increased in resistant cells as analyzed by electron spin resonance (ESR) and fluorescence anisotropy studies [98]. In addition, an increase in intramembranous particles and the rate of fluid-phase endocytosis are reported for resistant cells [99, 100]. 

The angles 6ex and 6em are the transition moment angles for excitation and emission respectively with respect to the center of the motional cone axis, with 9ex = 0° and 0em = S in this instance. The average tilt angles of the chromophores within the monolayers are provided in Table 5.3. Fluorescence anisotropy studies on BDP and QDP monolayers on silica reveal no decay of R(t), implying there is no chromophore motion on the time-scale being investigated. 

Titolo S et al (2003) Characterization of the minimal DNA binding domain of the human papillomavirus el helicase fluorescence anisotropy studies and characterization of a dimerization-defective mutant protein. J Virol 77(9) 5178-5191... 

Fluorescence depolarisation studies on mixtures of isotactic and syndiotactic polymethylmethacrylate have shown the formation of a 1 2 complex in toluene while fluorescence anisotropy studies on polybutadienes have shown viscous rotational diffusion with slipping boundary conditions OS. Fluorescence studies on quasi-rigid-rod like probes in anisotropic polyethylene have shown... 

Kudryasheva NS, Nemtseva EV, Visser AJWG, van Hoek A. Interaction of aromatic compounds with Photobacterium leiognathi luciferase fluorescence anisotropy study. Luminescence 2003 18 156-61. 

Bilsel, O., Yang, L., Zitzewitz, J. A., Beechem, J. M. and Matthews, C. R. 1999, Time-Resolved Fluorescence Anisotropy Study of the Refolding Reaction of the a-Subunit of Tryptophan Synthase Reveals Nonmonotonic Behavior of the Rotational Correlation Time. Biochemistry 38, 4177 - 4187. 

E. Deprez, P. Tauc, H. Leh, J-F. Mouscadet, C. Auclair, M.E. Hawkins, J-C. Brochon, DNA binding induces dissociation of the multimetric form of HIV-1 integrase A time-resolved fluorescence anisotropy study, PNAS 98, 10090-10095 (2001)... 

Chang CW, Lu YC, Wang TT, Diau EWG. 2004. Photoisomerization dynamics of azobenzene in solution with SI excitaion a femtosecond fluorescence anisotropy study. J Am Chem Soc 126 10109 10118. 

Fluorescence anisotropy studies are popular in biological and biochemical research of lipid membranes [16-18], proteins [19-22], etc. and also in polymer science. They have been performed for monitoring the conformations and flexibility of polymer chains in dilute, semidilute and concentrated solutions [23-27], in polymer melts and blends [28-31], and also for studying polymer self-assembly [32-34]. Nowadays, steady-state and time-resolved fluorescence anisotropy are currently used methods in polymer chemistry. 

In time-resolved fluorescence anisotropy studies the orientational motion of a fluorescent label rigidly affixed to a point on the chain, or that of a probe dissolved in the system, are studied. These experiments yield directly the time decay of the second orientational autocorrelation function, MaCx), associated with the unit vector m(x) along the transition moment of the chromophore at time X. M2(x) is given by... 

References (21-23) describe time-resolved fluorescence anisotropy studies (using TMA-DPH and DPH as fluorescent probes), of the effect of immime complexes on macrophage membrane fluidity, the effect of succinate and phenyl succinate on the fluidity of the inner mitochondrial membrane, and the role of cholesterol in modulating the fluidity of renal cortical brush border and basolatered membranes, respectively. 

A time-resolved fluorescence anisotropy study of the base motions in DNA, made using the intrinsic fluorescence of the bases themselves is described in (24). Large amplitude motions were found on the picosecond timescale that are sensitive to solvent viscosity. This provides support for the idea that base motions contribute substantially to the observed fluorescence depolarization in DNA and is consistent with a mechanism that involves concerted motions in the interior of the polymer. 

Yeow EKL, Ghiggino KP, Reek JNH, Crossley MJ, Bosnian AW, Schenning APHJ, and Meijer EW. The dynamics of electronic energy transfer in novel multiporphyrin functionalized dendrimers A time-resolved fluorescence anisotropy study. J. Phys. Chem. B 2000 104 2596-2606. 

Fluorescence anisotropy studies are very common in biochemical and biological research. They have been widely used in the past two decades to study the structures of various biological membranes formed by lipid bilayers [113-117]. Hence, a number of appropriate models have been proposed for interpretation of the experimental data for membranes and other organized biopolymer systems. In spite of the fact that this review is aimed at synthetic polymers and does not concern biopolymers and biologically important systems, the motion of probes embedded in dense 2D polymer brushes and in dense inner parts of coronas of self-organized polymeric nanoparticles is similar to that studied in biological membranes and therefore it will be mentioned. 

Chee CK, Hunt BJ, Rimmer S, Soutar I, Swanson L (2011) Time-resolved fluorescence anisotropy studies of the cononsolvency of poly(N-isopropyl acrylamide) in mixtures of methanol and water. Soft Matter 7(3) 1176-1184. doi 10.1039/c0sm00836b... 

Fluorescence anisotropy studies of concentrated solutions are important for two reasons. Firstly, they bridge the gap between the results for dilute solutions, which can be interpreted relatively easily on the basis of the existing models, and the practically important dynamic behavior of bulk polymers, which is very complicated and its theoretical description and appropriate analysis are difficult. SecOTidly, they elucidate the contribution of the local frictirai to the macroscopic viscosity rj c,T,M) of concentrated polymer solutions. The viscosity coefficient where c is the polymer concentration, M is its molar mass, and T is temperature, can be expressed as... 

Chee CK, Riuuner S, Soutar I, Swanson L (1997) Time-resolved fluorescence anisotropy studies of the temperature-induced intramolecular conformational transition of poly (N-isopropylacrylamide) in dilute aqueous solution. Polymer 38(2) 483 86. doi 10.1016/ s0032-3861(96)00636-2... 

Haas JA, Fox BG. 2002. Fluorescence anisotropy studies of enzyme-substrate complex formation in stearoyl-ACP desaturase. Biochemistry 41 14472-14481. 

A number of macromolecular diffusion and conformational properties can be studied using fluorescence anisotropy, fluorescence correlation spectroscopy (ECS), and fluorescence recovery after photobleaching (FRAP). These techniques most commonly are applied to proteins labelled with highly fluorescent probes, but can exploit intrinsic fluorescence in some instances. In fluorescence anisotropy studies, polarized light is used to selectively excite molecules whose transition dipole moments are aligned with the electric field vector. Steady-state... 

G. S. Jas, Y. Wang, S. W. Pauls, C. K. Johnson, and K. Kuczera, /. Chem. Phys., 107, 8800 (1997). Influence of Temperature and Viscosity on Anthracene Rotational Diffusion in Organic Solvents Molecular Dynamics Simulations and Fluorescence Anisotropy Study. 

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