Free energy diagram for the conformational spread model a) symmectric case: the free energy of conformational change is ±EA.
The free energy of CheY-P binding is dependent on the CheY-P concentration as shown, with EC = −ln(c/c0.5). If EC>0, the inactive state becomes more highly populated and hence CW bias <0.5, while EC<0 similarly implies CW bias >0.5. b) asymmetric case: the free energy of conformational change is ±EA0 when a protomer is unliganded and ±EA1 when it is liganded. c) coupling energy EJ between neighboring protomers.