Abstract
The equality of information content in fluorescence polarization and emission anisotropy is a common assumption and the two quantities are used according to practical considerations. However, an information-theoretic analysis presented here reveals that their information content is substantially different. A scaling relation exists between polarization and anisotropy, and normalization allows their direct comparison. Various measures of information such as the absolute, relative, differential, and potential entropies all appear larger for anisotropy over part or all of its normalized overlap with the polarization function. The larger information content coincides with the signal range where the emitted light is polarized mostly in the parallel direction. Polarization takes on larger absolute entropy only when the emission is about perpendicular to the incident light and when the differential entropy is considered over the entire physical domain. The additional information locally afforded by polarization appears to be related to its larger signal range whereas the extra information in anisotropy may be attributed to a second perpendicular emission plane in its definition, which is oriented along the axis of propagation of light and takes the contribution of all degrees of rotational freedom into account. Thus anisotropy may be considered as a more accurate and more informative representation of the underlying physical phenomena. Some practical aspects relevant to studies of protein–ligand interactions are also discussed.
Similar content being viewed by others
References
Lakowitz JR (1999) Principles of fluorescence spectroscopy, 2nd edn. Kluwer Academic(Plenum Publishers, New York
Sharma A, Schulman SG (1999) Introduction to fluorescence spectroscopy. Techniques in analytical chemistry series. John Wiley and Sons, Inc, New York
Valeur B (2002) Molecular fluorescence. Principles and applications. Wiley-VCH Verlag GmbH, Weinheim, Germany
Jameson DM, Croney JC, Moens PD (2003) Fluorescence, basic concepts, practical aspects and some anecdotes. Methods Enzymol 360:1–43
Weber G (1952) Polarization of the fluorescence of macromolecules. 1. Theory and experimental method. Biochem J 51:145–155
Weber G (1953) Rotational Brownian motion and polarization of fluorescence of solutions. Adv Protein Chem 8:415–459
Jablonski A (1960) On the notation of emission anisotropy. Bull Acad Polon Sci Ser Sci Math Astr et Phys 6:259–264
Weber G (1966) Polarization of the fluorescence of solutions. In: Hercules D (ed) Fluorescence and phosphorescence. Wiley, New York, pp 217–240
Jameson DM, Sawyer WH (1995) Fluorescence anisotropy applied to biomolecular interactions. Methods Enzymol 246:283– 300
Jameson DM, Croney JC (2003) Fluorescence polarization, past present and future. Comb High Throughput Chem 6:167–173
Jameson DM, Mocz G (2005) Fluorescence polarization(anisotropy approaches to study protein-ligand interactions, Effects of errors and uncertainties. In: Nienhaus GU (ed) Methods in molecular biology. Protein–ligand interactions: methods and applications, vol 305. Humana Press Inc., Totowa, NJ, pp 301–322
Yguerabide J (1972) Nanosecond fluorescence spectroscopy of macromolecules. Methods Enzymol 26:498–578
Wahl Ph (1975) Fluorescence spectroscopy. In: Chen RF, Edelhoch H (eds) Biochemical fluorescence concepts, vol. 1. Marcel-Dekker, New York, pp 1–41
Shannon CE (1948) A mathematical theory of communication. Bell Syst Technol J 27(379–423):623–656
Shannon CE, Waever W (1949) Mathematical theory of communication. University of Illinois, Urbana
Brillouin L (1956) Science and information theory. Acad Press, New York
Brillouin L (1964) Scientific uncertainty and information. Acad. Press, New York
Kullback S, Leibler RA (1951) On information and sufficiency. Ann Math Stat 22(1):79–86
Kullback S (1959) Information theory and statistics. John Wiley & Sons, Inc., New York
Khinchin AI (1957) Mathematical foundations of information theory. Dover Publications, Inc., New York
Eckschlager K, Stepanek V (1979) Information theory as applied to chemical analysis. John Wiley and Sons, New York
Danzer K, Hopfe V, Marx G (1982) Möglichkeiten der Erhörung der Informationsmenge spectroskopischer Analysenmethode mit Hilfe der Rechentechnik. Z Chem 22:332–338
Hauser MD (1996) The evolution of communication. The MIT Press, Cambridge, Massachusetts
Bonchev D (1983) Information theoretic indices for characterization of chemical structures. Research Studies Press, Chichester, England
Eckschlager K, Stepanek V (1985) Analytical measurement and information. Advances in the information theoretic approach to chemical analyses. Research Studies Press Ltd. Letchworth, Hertfordshire, England
Eckschlager K, Danzer K (1994) Information theory in analytical chemistry. John-Wiley & Sons, Inc., New York
Magurran A (1988) Ecological diversity and its measurement. Princeton University Press, Princeton, New Jersey
Guiasu S (2001) Quantum mechanics. Nova Science Publishers, Huntington, New York
Alcala JR, Gratton E, Prendegrast FG (1987) Interpretation of fluorescence decays in proteins using continuous lifetime distributions. Biophys J 51:925–936
Lakowicz JR, Gryczynski I, Wiczk W, Johnson ML (1994) Distributions of fluorescence decay times for synthetic melittin in water-methanol mixture and complexed with calmodulin, troponin C, and phospholipids. J Fluoresc 4:169–177
Bronchon JC (1994) Maximum entropy method of data analysis in time-resolved spectroscopy. Methods Enzymol 240:262–311
van der Heide UA, Hopkins SC, Goldman YE (2000) Maximum entropy analysis of protein orientation using fluorescence polarization data from multiple probes. Biophys J 78:2138–2150
Sengupta P, Garai K, Balaji N, Periasamy N, Maiti S (2003) Measuring size distribution in highly heterogeneous systems with fluorescence correlation spectroscopy. Biophys J 84:1977– 1984
Ash RB (1965) Information theory. Interscience, New York, New York
Levine RD, Tribus M (eds) (1979) The maximum entropy formalism. MIT Press, Cambridge, Massachusetts
Cover TM, Thomas JA (1991) Elements of information theory. John Wiley & Sons, Inc.
O’Neill EL (1963) Introduction to statistical optics. Addison-Wesley, Reading, MA
Smith JDH (2001) Some observations on the concepts of information-theoretic entropy and randomness. Entropy 3:1–11
Perrin F (1926) Polarisation de la lumière de fluorescence. Vie moyenne des molécules dans l‘etat excitè. J de Phys. VIe Sèrie 7:390–401
Press WH, Flannery BP, Teukolsky AA, Vetterling WT (1989) Numerical recipes in pascal. The art of scientific computing. Cambridge University Press, NY
Renyi A (1965) On the foundations of information theory. Rev Intern Stat 3:1–14
Desper CR, Kimura I (1967) Mathematics of the polarized-fluorescence experiment. J Appl Phys 38:4225–4233
Badley RA (1976) Fluorescent probing of dynamic and molecular organization of biological membranes. In: Wehry EL (ed) Modern fluorescence spectroscopy. Plenum Press, New York, pp 91– 168
Picozzi A (2004) Entropy and degree of polarization for nonlinear optical waves. Opt Lett 29:1653–1655
Wahl Ph (1979) Analysis of fluorescence anisotropy decays by a least squares method. Biophys Chem 10:91– 104
Reflegler P (2005) Polarization degree of optical waves with non-Gaussian probability density functions, Kullback relative entropy-based approach. Opt Lett 30:1090–1092
Acknowledgements
The author wishes to thank Professor David M. Jameson for his thoughtful comments and valuable discussions. This work was supported, in part, by a grant from the National Institute of Health (NIH/NCRR/RCMI G12-RR03061: Selective Research Excellence in Biomedicine and Health).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mocz, G. Information Content of Fluorescence Polarization and Anisotropy. J Fluoresc 16, 511–524 (2006). https://doi.org/10.1007/s10895-006-0095-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10895-006-0095-7