Figure 4. Agonist efficiency versus head-group volume.
Efficiencies were calculated from CRCs (n=13) or from single-channel kinetics (n=5). Crosses mark centroids of two clusters: η=52±2%, volume=70±8 A3 (red) and η=40±5%, volume=101±11.2 A3 (blue). Ebx from CRC analysis (gray) was excluded from the cluster analysis. Larger-volume agonists have lower efficiencies.