Figure 2.

(A) Initial rate of [³H]Tyr or [³H]Trp uptake by proteoliposomes incorporating LeuT^K and binding site variants. Error bars indicate s.e.m., n=2–5. (B) Saturation binding of [³H]Trp to LeuT^K and variants measured by scintillation proximity assay. LeuT^K: circles with solid line; F259V: triangles with dashed line; I359Q: inverted triangles with dotted line; F259V+I359Q: squares with dash-dot line. Error bars indicate s.e.m., n=2. (C) Steady-state kinetic measurement of [³H]Trp uptake by LeuT^K+I359Q fitted with Michaelis–Menten rectangular hyperbola. Error bars represent s.e.m., n=3.