Fig. 5.

Single-channel currents recorded from Y914 and Y917 mutant channels in inside-out membrane patches. a Example single-channel currents carried by the named channel variants at a membrane potential of − 50 mV. The closed state is indicated by the line to the far left. Note that only very brief, incompletely resolved openings were observed for Y917A, as well as for Y917S and Y917V (data not shown). Mean single-channel current (i)–voltage (V) relationships for Y914 (b) and Y917-substituted channels (c) as indicated. d Mean single-channel conductance measured from the slope of the  i –V relationship from individual patches. Asterisks indicate a significant difference from wild-type (p < 10⁻⁶). Mean of data from 5 to 9 patches