Figure 3.

H₂S does not inhibit Kv2.1 C73A but inhibit other recombinant mutant forms. (A) Bar graph showing normalised mean (± s.e.m.) effect of NaHS in wild-type (WT), C73A, C29A and C831A mutants of Kv2.1, as indicated (**indicates P < 0.01 and ***indicates P < 0.001 with the number of cells tested in parentheses). (B) Example time-series plot illustrating normalized current amplitudes evoked by step-depolarizations from − 70 to + 50 mV in a C73A Kv2.1-expressing HEK293 cell. For the period indicated by the horizontal bar, NaHS (250 µM) was applied via the perfusate. Inset shows example currents before and during NaHS application, as indicated. (C) Example time-series plot as in (B) for C29A Kv2.1-expressing HEK293 cell. For the period indicated by the horizontal bar, NaHS (250 µM) was applied via the perfusate, with irreversible effect upon washout for the time period indicated by the horizontal bar. Inset shows example currents before and during NaHS application for C29A, as indicated. (D) Same as in (B and C) except the example time-series plot illustrating a C831A Kv2.1-expressing HEK293 cell before and during application of NaHS (250 µM) for the period indicated by the horizontal bar, as in (C) the effect was irreversible upon washout, indicated by the horizontal bar. Inset shows example currents before and during NaHS application for C831A. Scale bars: 0.5 nA (vertical) and 50 ms (horizontal).