Conformational energy and circular dichroism computed for cyclo-(pro-gly)3

An analytic cyclization procedure has allowed the complete specification of c-(Pro-Gly)₃ conformation by three dihedral angles. Utilizing this simplification, the intramolecular potential energy of c-(Pro-Gly)₃ has been computed over all of conformational space. Conformers with all peptide bonds trans have the lowest total potential energy. Circular dichroism spectra calculated for the low-energy regions provide the basis for the interpretation of experimental CD spectra.