Combined effects of allosteric agonist on binding affinity and operational efficacy. Effects of positive (top) and negative (bottom) modulation of binding affinity and negative (left) and positive (right) modulation of operational efficacy. EMAX = 1, τA = 3, τB = 1, values of factors of cooperativity α and β are indicated within the plots. Meta-analysis of concentration–response curves is in Supplementary information Figs. S3 and S4.