... that the conformationalspace of b-aminoacidsislargerthanthatofa-aminoacids, but low-energy conformations of the b-amino acidsbackbone, corresponding to gauche rotamers around the Ca–Cb bond, ... 9825–9832.34. Sachon, E., Girault-Lagrange, S., Chassaing, G., Lavielle, S. &Sagan, S. (2002) Analogs of Substance P modified at the C-terminus which are both agonist and antagonist of the NK-1receptor ... potentialenergy surfaces the conformers of b-amino acids that fitwith canonical conformations of a- amino acids, two(/ ) w) Ramachandran maps corresponding to h torsionangle values of +60°,gauche(+),or)60°,...