Figure 9.

(a) The relative donor lifetime (τ_D^A/τ_D⁰) and (b) acceptor lifetime (τ_A⁰/τ_D⁰) and the total mean acceptor delay time of the unfolded state ((τ_DU^A + τ_AU⁰)/τ_D⁰, diamond) obtained from the maximum likelihood analysis of the photon trajectories including acceptor delay time information. The donor excited state lifetime distribution of the folded state was approximated to be single-exponential and that of the unfolded state was approximated to be either single-exponential (2-state/AD, eq 14) or bi-exponential (2-state/AD2, eq 15). Parameters are also listed in Table S1. The lifetimes in the folded (circle) and unfolded (square) states were determined using the pre-determined FRET efficiencies, rate coefficients and donor lifetimes in the donor channel.