1: Biophys J  1982 Feb;37(2):461-4 

On the wobbling-in-cone analysis of fluorescence anisotropy decay.

Kinosita K Jr, Ikegami A, Kawato S.

Interpretation of fluorescence anisotropy decay for the case of restricted
rotational diffusion often requires a model. To investigate the extent of model
dependence, two models are compared: a strict cone model, in which a fluorescent
probe wobbles uniformly within a cone, and a Gaussian model, where the
stationary distribution of the probe orientation is of a Gaussian type. For the
same experimental anisotropy decay, analysis by the Gaussian model predicts a
smaller value for the rate of wobbling motion than the strict cone analysis, but
the difference is 35% at most; the cone angle obtained by the strict cone
analysis agrees closely with the effective width of the Gaussian distribution.
The results suggest that, when only two parameters (the rate and the angular
range) are extracted from an experiment, the choice of a model is not crucial as
long as the model contains the essential feature, e.g., the more-or-less conical
restriction, of the motion under study. Model-independent analyses are also
discussed.

PMID: 7059650 [PubMed - indexed for MEDLINE]