Fig. 4.

DTNB, a specific oxidant of cysteine residues, facilitates Ca²⁺ channel activity in inside-out mode. a Time course of channel activity recorded first in the cell-attached (c.a.) mode followed by the inside-out (i.o.) mode. After patch excision, 1 μM CaM + 3 mM ATP was applied to maintain channel activity, and then DTNB (1 mM) was additionally applied. b Example of current traces for control in c.a. mode (a), with CaM + ATP in i.o mode (b), and with CaM + ATP + 1 mM DTNB (c) at the time period indicated in (a). c Summary of normalized channel activity in the presence of CaM + ATP and CaM + ATP + DTNB (n = 5). Data are shown as mean ± SE. *P < 0.05 versus control (t test)