Residue Phe266 in S5-S6 loop is not critical for Charybdotoxin binding to Ca~(2+)-activated K~+(mSlo

• 出 处: Acta Pharmacologica Sinica
• 发表日期: 2006年07期
• 关键词: Residue dissociation opposed insight mutagenesis residue HEPES residues stacking

Aim:To gain insight into the interaction between the Charybdotoxin(ChTX)andBK channels.Methods:Site-directed mutagenesis was used to make two mutants:mSlol-F266L and mSlol-F266A.The two mutants were then expressed in Xeno-pus oocytes and their effects were tested on ChTX by electrophysiologyexperiments.Results:We demonstrate an equilibrium dissociation constant K_d=3.1—4.2 nmol/L for both the mutants mSlol-F266L and mSlol-F266A similar to thatof the wild-type mSlol K_d=3.9 nmol/L.Conclusion:The residue Phe266 does notplay a crucial role in binding to ChTX,which is opposed to the result arising fromthe simulation of peptide-channel interaction.

Aim: To gain insight into the interaction between the Charybdotoxin (ChTX) and BK channels. Methods: Site-directed mutagenesis was used to make two mutants: mSlol-F266L and mSlol-F266A. The two mutants were then expressed in Xeno-pus oocytes and their effects were tested on ChTX by electrophysiology experiments. Results: We demonstrated an equilibrium dissociation constant K_d = 3.1-4.2 nmol / L for both the mutants mSlol-F266L and mSlol-F266A to that of the wild-type mSlol K_d = 3.9 nmol / L . Conlusion: The residue Phe266 does not play a crucial role in binding to ChTX, which is opposed to the result arising from the simulation of peptide-channel interaction.