Fig. 4.

Langevin simulation results for protein L and CspTm. (A) Donor–acceptor distance distributions for folded protein L (black line) and CspTm (red line). The N- and C-terminal α carbons are separated by 38 Å and 13 Å in the structures of protein L and CspTm, respectively. (B) Decay of correlation functions for donor–acceptor distance (black line), reorientation of the donor (green line) and acceptor (red line), and κ² (blue line). (C) Decay of donor fluorescence in protein L calculated with (red lines) and without (black lines) the assumption of complete orientational averaging; curves for the folded and unfolded states are solid and broken, respectively, and the isolated donor decay is shown for reference in green.