FIGURE 2.
Kinetics of mini-Pg activation by SK and SK mutants. A and B, v1 as a function of the total SK or SK mutant concentration ([SK]o) and v2 as a function of log total SK or SK mutant concentration ([SK]o), respectively, for wtSK in the absence (●) and presence of 10 mm 6-AHA (○), native SK in the absence (▴) and presence of 10 mm 6-AHA (▵), and SKΔ414 in the absence (■) and presence of 10 mm 6-AHA (□). C and D, v1 and v2, respectively, as in A for SKΔ(R253-L260) in the absence (●) and presence of 10 mm 6-AHA (○) and SK(R253A) in the absence (▴) and presence of 10 mm 6-AHA (▵). E and F, v1 and v2, respectively, as in A for SK(K256A) in the absence (●) and presence of 10 mm 6-AHA (○), SK(K257A) in the absence (▴) and presence of 10 mm 6-AHA (▵), and SK(K256A/K257A) in the absence (■) and presence of 10 mm 6-AHA (□). Solid lines represent the nonlinear least-squares fits to the data with Equations 2 and 4 for v1 and Equations 3 and 4 for v2 with the parameters listed in Table 1. Kinetic data were collected and analyzed as described under ”Experimental Procedures.“