Fig. 5. Representative current/voltage (I/V) relationships elicited by free amino acids in 100 mmoll^-1 Na⁺ medium. The I data represent total currents obtained by substracting control I/V data from the I/V data in the presence of 0.5 mmoll^-1 amino acids for (A) CAATCH1 WT and (B) CAATCH1 Y147F. In B, data were obtained using the same oocyte as Fig. 3C,D, demonstrating that currents elicited by Gly, Pro and Phe were similar to those in the presence of NMG⁺ alone. V_m, membrane potential.