Figure 4. Stable coordination of Cd²⁺ at T336C.

a, P2X₂-3T is insensitive to 20 μM Cd²⁺. Same experimental paradigm as in Fig. 1a. b, Superimposed scaled current traces for T336C showing that the current is rapidly inhibited by 20 μM Cd²⁺ in the presence of ATP. Only a fraction of the inhibitory effect reverses rapidly. c, Consecutive applications of ATP to T336C without Cd²⁺ application. d, Consecutive applications of ATP to T336C where 20 μM Cd²⁺ was applied for 30 s in the absence of ATP. e, Consecutive applications of ATP to T336C where Cd²⁺ was applied in the presence of ATP. Current records for c-e are from the same cell.