High concentrations of 2,3-BPG and carbon monoxide both inhibit the oxygen-carrying capacity of hemoglobin. The animation illustrates how 2,3-BPG binds at the interface of two β subunits and stabilizes the T state of hemoglobin. Carbon monoxide, on the other hand (as discussed in section 6.2 of the text), binds to the heme iron in the same manner as oxygen. Would you expect carbon monoxide binding to shift the conformational equilibrium in favor of the T state or the R state?