Journal of the American Chemical Society, Vol.118, No.18, 4249-4255, 1996
The Structure and Energetics of Helix Formation by Short Templated Peptides in Aqueous-Solution .3. Calculation of the Helical Propagation Constant-S from the Template Stability-Constants T/C for AC-Hel(1)-ALA(N)-Oh, N=1-6
From t/c values measured at 25 degrees C for the series Ac-Hel(1)-A(n)-OH, n = 1-6 in D2O the helical propagation constant (s value) for alanine in this templated peptide series is 1.03; the corresponding value in 10 mol % trifluoroethanol-D2O is 1.47. An iterative least squares analysis for calculating s values from t/c ratios is developed, errors implicit in its application are discussed, and the s value is related to the degree of helical fraying.