“…These include (1) for the nucleation process at 14.5 °C, the forward rate constant, k N = (104.7 ns) −1 , is smaller than the backward rate constant, k −N = (20.7 ns) −1 , which is consistent with the notion that the formation of an α-helix nucleus is a thermodynamically unfavorable event; 38, 40, 45, 77–80 (2) for the propagation process, the trend is reversed (for the temperature range considered), which is consistent with the notion that propagation leads to α-helix stabilization; 35, 38–40, 77, 79 (3) for the propagation process, the ratio between the forward rate constant and the backward rate constant is 2.5 for the M-region, 1.5 for the N-region and C-region, which is consistent with the fact that the middle region of an α-helix is more stable than its terminal regions; 12, 31, 35, 61, 63, 65, 81 and (4) using the value of k N , which is the rate constant of a single C→H transition involved in the nucleation process according to our model, we determine the time required to form a helical nucleus (i.e., the —CHHHC— state in our model) to be about 315 ns. This value is in close agreement with that (i.e., 400 ns) reported by Kiefhaber and cowokers 31 and that (i.e., 300 ns) reported by Werner et al 31, 82 for alanine-based peptides.…”