The mechanism for the conversion of the 13/4 helix into the 4/1 helix of poly(a -isobutyl b -L-aspartate) was simulated at the atomic level. A computational procedure based on a potential of mean force capable of creating multiple conformation states compatible with a given helical symmetry was used. Intermediate helical arrangements differing in 0.1 residues/turn were modeled and energetically evaluated to delineate the reaction coordinate. The conversion was found to proceed through poorly defined hydrogen bonded structures having an energy surplus of about 6 kcal/mol·residue. Results were consistent with experimental data and helpful for understanding fundamental aspects of the transition as it is observed in the solid state.
Посилання на статтю:
Conformational analysis of the 13/4 to 4/1 helical transition in poly(a -isobutyl b -L-aspartate) / Salvador León, David Zanuy, Carlos Alemán, Sebastián Muñoz-Guerra // Polymer. – 1999. – N 40. – P. 5647–5654.