Fig. 6.

GlyH-101 protection of T338C (an engineered cysteine at position 338) from MTSES⁻ but not from MTSET⁺. A, the T338C CFTR was reacted with 5 μM MTSES⁻ in the presence and absence of 10 μM GlyH-101. Data points represent mean ± S.E.M. (n = 3). The lines represent the best fits of single-exponential functions to the conductance data. The half-life of each single-exponential fit is shown. The MTSES⁻ reaction rate was almost 3 times slower in the presence of GlyH-101. The second-order reaction rate constants for MTSES⁻ in the presence and absence of 10 μM GlyH-101 were 1.2 × 10³ and 3.3 × 10³ M⁻¹ s⁻¹, respectively. B, the T338C CFTR was reacted with 50 μM MTSET⁺ in the presence and absence of 10 μM GlyH-101. Data points represent mean ± S.E.M. (n = 3). The presence of GlyH-101 had no impact on the MTSET⁺ reaction rate. The second-order reaction rate constants for MTSET⁺ in the presence and absence of GlyH-101 were 1.8 × 10² M⁻¹ s⁻¹.