Fig. 6.

Functional consequences of mutations at the TM3/TM4 interface. a, b Quantification of forward (α) and reverse (β) scrambling rate constants for WT and mutant nhTMEM16 in the presence (a) and absence of Ca²⁺ (b) determined by fitting fluorescence traces to Eq. 1 (“Methods”). For the WT protein in the presence of Ca²⁺ the rate constants could not be determined and were constrained to be 0.2 s⁻¹ as previously described^21,52. c Quantification of the fraction of liposomes containing at least one active ion channel in the presence (red) and absence (black) of Ca²⁺ using Eq. 3 (“Methods”). Error bars represent S.D. and the values of individual experimental replicates are indicated as symbols. n = 4–20 from 2 + independent preparations