Anisotropy Decay Analysis

Tleugabulova, D., Duft, A.M., Zhang, Z., Chen, Y., Brook, M.A. and Brennan, J.D. (2004) Evaluating formation and growth mechanisms of silica particles using fluorescence anisotropy decay analysis. Langmuir, 20, 5924—5932. 

GLOBAL ANISOTROPY DECAY ANALYSIS WITH MULTIWAVELENGTH EXCITATION... 

Cross A J and Fleming G R 1984 Analysis of time-resolved fluorescence anisotropy decays Blophys. J. 46 45-56... 

Lee, J., Wang, Y., and Gibson, B. G. (1990). Recovery of components of fluorescence spectra of mixtures by intensity- and anisotropy decay-associated analysis the bacterial luciferase intermediates. Anal. Biochem. 185 220-229. 

With the development of multifrequency phase-modulation technology, Lakowicz and co-workers(171) were able to examine the time dependence of the anisotropy decay of BPTI. They noted that the intensity decay of the fluorescence is best fit by a biexponential decay law and that the anisotropy decay is also complex. At 25 °C and pH 6.5, correlation times of 39 ps and 2.25 ns were recovered from analysis of data obtained over the range 20 MHz to 2 GHz. The longer correlation time is close to that predicted for the overall rotational motion of a molecule of the size of BPTI. They indicated, however, that additional experiments need to be done to resolve whether the 39-ps... 

K. Kinosita, Jr., S. Kawato, and A. Ikegami, Dynamic structure of biological and model membranes Analysis by optical anisotropy decay measurement, Adv. Biophys. 17, 147-203 (1984). 

Extensions of the analysis of time-resolved fluorescence anisotropy decay data in terms of two order parameters have also been developed (see, e.g., Refs. 51-54). Thus, the corresponding higher order parameter term is <7%) given by(53)... 

M. Straume and B. J. Litman, Influence of cholesterol on equilibrium and dynamic bilayer structure of unsaturated acyl chain phosphatidylcholine vesicles as determined from higher order analysis of fluorescence anisotropy decay, Biochemistry 26, 5121-5126 (1987). 

L. Davenport, J. R. Knutson, and L. Brand, Anisotropy decay associated fluorescence spectra and analysis of rotational heterogeneity. 2. l,6-Diphenyl-l,3,5-hexatriene in lipid bilayers, Biochemistry 25, 1811-1816 (1986). 

J. R. Lakowicz, H. Cherek, I. Gryczynski, N. Joshi, and M. L. Johnson, Enhanced resolution of fluorescence anisotropy decays by simultaneous analysis of progressively quenched samples, Biophys. J. 51, 755-768 (1987). 

Allison, S.A., Austin, R., and Hogan, M. (1989) Bending and twisting dynamics of short linear DNAs-analysis of the triplet anisotropy decay of a 209-base pair fragment by Brownian simulation. J. Chem. Phys. 90, 3843-3854. 

In the present study we investigated energy transfer between the Zn-porphyrin units in a sequence of dendrimers varying in size from 4 to 64 porphyrin units (Fig. 1). Reference measurements were performed on the monomer, P1D1. In order to follow energy transfer within the dendrimers, the fluorescence anisotropy decay were analysed. To determine the lifetime of the dendrimers, additional analysis of the kinetics measured at magic angle was performed. The fluorescence anisotropy is defined by... 

Fluorescence anisotropy decay can also be measured by frequency-domain methods. In this approach, the polarized fluorescence intensities 7 (oo) and 7j (oo) are measured as a function of the modulation frequency of the polarized excitation beam. Even more information about frequency-domain anisotropy measurement and analysis can be found in the monograph by Lakowicz (see Eurther Reading). 

Fluorescence anisotropy measurements can also be used to obtain the rates of the excited state tautomerization. Two variants can be applied. The first is based on the analysis of time-resolved anisotropy curves. These are constructed from measurements of the fluorescence decay recorded with different positions of the polarizers in the excitation and emission channels. The anisotropy decay reflects the movement of the transition moment and thus, the hydrogen exchange. For molecules with a long-lived Sj state, the anisotropy decay can also be caused by rotational diffusion. In order to avoid depolarization effects due to molecular rotation, the experiments should be carried out in rigid media, such as polymers or glasses. When the Sj lifetime is short compared to that of rotational diffusion, tautomerization rates can be determined even in solution. This is the case for lb, for which time-resolved anisotropy measurements have been performed at 293 K, using a... 

For the probes 9-methyl anthracene (MA) and DMA solubilized in the hypercoiled conformation of PMAA, the anisotropy decays could best be described by invoking double-exponential analysis of the form described by Equation 2.32... 

In this analysis of the fluorescence and fluorescence anisotropy decay, the entropy of the cross-product a(x). P(( )) is maximized under the constraint of minimum %, ... 

Quenching studies of protein fluorescence provide answers regarding the accessibility of certain internal or external groups to quencher molecules. Another application concerns the study of associative behavior and properties of proteins and membranes. The rationale is that the fluorescence transition is polarized and this polarization can be exploited in time-resolved analysis and interpreted in terms of the rotation or tumbling motion which in turn is determined by the viscosity and structure of the environment of the fluorescing group. In particular, anisotropy decay studies have yielded a great deal of information on the mobility of natural and artificial membranes and/or the dynamics of proteins as well as small molecules in membranes. For such studies fluorescence lifetime labels that can be attached to proteins or that dissolve in membranes have... 

In the anisotre decay analysis, the value of ro can be considered to be a known CH an unknown value. If the value of ro is known, the anisotropy decay law can be writtoi m... 

In the FD analysis, the rolation- ee intensity deaqr is measured in a separate experiment using magic-anp polarizer conditions. The parameter vahiea, typically 0 and t fur the midtiexpaoential model, are held constant during the calculation of xJ Bq. [11.34]. In principle, one could measure the phase and modulation of the polarized components and use these data to recover Jff) and fft). This would be analogous to the method used for TCSPC data. However, it is believed that the anisotropy decay is better determined by direct measurement of the difference (i .) and ratio (A ) values. 

While the use of glc al analysis with quoiching is us ul for studies of rigid anisotropic rotors Ais method is even more useful in studies of complex anisotropy decays from proteins. This is because the correlation times for segmra-tal motions and overall rotations of a protein are usually quite different in magnitude, whereas the correlation dmes of a rigid rotor are usually similar in magnitude. 

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