Figure 4

Redox modification influences the activity of purified hTRPA1 without its N-terminal ankyrin repeat domain (Δ1-688 hTRPA1).

Representative traces show single channel activity for Δ1-688 hTRPA1 when inserted into planar lipid bilayers and exposed to cold (15 °C) or the oxidant H₂O₂ (100 μM) at 22 °C. The cold-evoked channel activity was inhibited by the reducing agents TCEP (1 mM, n = 4) and DTT (5 mM, n = 3) and as shown with TCEP the effect was reversible. The single channel mean open probability (Po) and conductance (Gs) values for cold were 0.46 ± 0.05 and 31 ± 6 pS, respectively (n = 6). The Po and Gs values for H₂O₂ were 0.16 ± 0.05 and 57 ± 8 pS, respectively (n = 6). The channel activity evoked by H₂O₂ was inhibited by TCEP (1 mM, n = 3). Channel currents were recorded with the patch-clamp technique a test potential of +60 mV in a symmetrical K⁺ solution (c indicates the closed channel state).