Functional analysis of human Na+/K+-ATPase familial or sporadic hemiplegic migraine mutations expressed in Xenopus oocytes

Figure 3 Apparent K⁺ affinity. A-E: K_0.5 values for the [K⁺]_ex dependence of stationary currents at different membrane potentials for the RD-WT enzyme (E) and the mutants G900R (A), E902K (B), D999H (C) and K1003E (D), as calculated from fits of a Hill function to the data in Figure 2, respectively. Data were approximated with polynomial functions of second or third (D999H) grade to determine the minimum. The curve derived from RD-WT data is superimposed as dotted line for comparison. An “a” indicates that the data point was significantly different from the RD-WT data (^aP < 0.05 vs RD-WT, Student’s t-test). Data are means ± SE obtained from 5-15 cells of at least three batches.