Time-resolved fluorescence anisotropy decay.

фfast and фslow are fast and slow anisotropic decay rotational correlation times, while βfast and βslow are corresponding amplitudes. r0 is intrinsic (time zero) fluorescence anisotropy. rss is steady state anisotropy estimated from time-resolved fluorescence anisotropy decay experiments. τm is mean fluorescence lifetime obtained by magic angle measurements (Fig. S4 and Table S1). Both τm and ф are in ns. χ2 is a measure of goodness of fit. Closer the value to 1, better is fitting.