FIGURE 6.

The influences of arginine substitution and modification of engineered cysteine substitution by MTS reagents upon the single-channel conductance (γ) of the 5-HT₃A(QDA) receptor. A, plot depicting the strong correlation (r² = 0.89) between the change in γ produced by arginine substitution and by the reaction of substituted cysteine residues by positively charged MTSEA at residues 431–441, inclusive, both compared with alanine. B, inclusion of residues 426–430 at which the presence of arginine was associated with an increase in conductance versus alanine controls weakens the correlation (r² = 0.58). C, correlation (r² = 0.68) between the magnitude of the increase in γ produced by challenge with MTSES versus the γ of the construct without exposure to the MTS reagent.