Fig. 4.
Time dependence of the instantaneous rate constant kinst(t) for thiyl radical recombination after photolysis of an aromatic disulfide cross-linker. Shown are the results for N-PGK (black), two separate measurements on the picosecond timescale in the absence of urea and measurements on the nano- to millisecond timescale in the presence of 2 M and 8 M urea, respectively, and α-helical model peptides (22) (blue). Solid lines are the results of power law fits; also given are the powers obtained from these fits.