Table 2. Properties and occupancy of the two activity states in the Heeley et al. (2019) two-state model
StatesIA
ATPaseLowHigh
Occupancy+Tn −Ca0.95 (0.95)0.05 (0.05)
+Tn +Ca0.25 (0.8)0.75 (0.2)
+Myosin (ratio of myosin: actin, 1:7)0.33 (0)0.67 (1.0)

The occupancy is based on the Keq values given in Scheme 2 of Heeley et al. (2019) where Keq is the equilibrium constant between the A and I states. The values in brackets are the occupancies predicted by the earlier two-state model of Hill et al. (1980).