Topological reconstruction of the backbone dipoles from ref. 148. Top inset: the relative orientation (θ) of a backbone dipole μ with respect to the internal reference system by three consecutive C_α's is determined by the angle γ, according to the relationship represented in the right inset. The stars indicate statistical distribution of (γ,θ) angles from the PDB databank (green=helical coiling, yellow=extended structures). Main graph: macromolecular electrostatic dipole along the longitudinal axis of a helical peptide undergoing unfolding by application of a longitudinal stretching force. The black line represents the estimate of the macromolecular dipole from an AA model, the red line is the prediction by the CG reconstruction.