Application of the Dale-Eisinger analysis to proximity mapping in the contractile system.

Fluorescence anisotropy decays were used to quantify the degree of rapid librational motion associated with several fluorescent probes attached to contractile proteins. This information allows an analysis of how far kappa 2, the resonance energy transfer orientation factor, may deviate from the dynamically averaged value of 2/3. Extrema can then be set on R0, the critical transfer distance, and hence on the interprobe distance. These results set maximum ranges on possible distances between several probe pairs used in the mapping of contractile protein structure by resonance energy transfer.