Structural analysis. Representative trajectories of the top 2 (blue and red) most populated groups from hierarchical cluster analysis superimposed on the active GPRP or GPRV conformation (green); GPRPxxx peptides were compared with active GPRP and GPRVxxx peptide were compared with active GPRV. (A) GPRPAAC, (B) GPRPFPAC, (C) GPRPPERC, (D) GPRVVERC, and (E) GPRVVAAC. (F) The population percentage represents the percentage of total number trajectories in 1 conformational cluster; the top 2 populated clusters at the fourth level of the hierarchical cluster are reported. RMSD calculations for the first 3 residues were in reference to the active conformation (ie, GPRP or GPRV); both backbone and total RMSDs were calculated after optimal superposition along the backbone.