A Pentasymmetric Open Channel Blocker for Cys-Loop Receptor Channels
Figure 8
PCCP− prevents the increase in PCCP− sensitivity of α1V256β2γ2 mediated by MTSET+ + GABA.
GABA (EC10) was applied repetitively until a stable current response was observed followed by inhibition of the channel by PCCP−. Subsequently 5 mM MTSET was applied in the presence of GABA. After MTSET+ treatment GABA was applied twice followed by a combined application of GABA and the same concentration of PCCP− used before. A, Wild type receptors were not affected by this treatment. B, The treatment leads to an enhanced inhibition in α1V256Cβ2γ2. C, 5 mM MTSET+ was applied to α1V256C mutant receptor in presence of GABA and 1 mM PCCP−. PCCP− prevented enhanced inhibition and therefore covalent reaction. These experiments were repeated independently three times using different oocytes.