Figure 2

Effect of Ca²⁺ on MAO-A substrate kinetics in HT-22 hippocampal cell line. (A) HT-22 cell lysates (100 μg/100 μL; n = 3) were incubated with increasing concentrations of substrate, e.g. [¹⁴C]-5-HT in the absence (○) or presence (●) of Ca²⁺ (1 mM). The individual curves represent data pooled from three independent experiments. Data are presented as mean ± SD. (B) The highlighted part of the curves in (A) is expanded to demonstrate the change in K_m. (C) Data presented on a double-reciprocal plot clearly demonstrate a change in slope (e.g. K_m/V_max) with no change in y-intercept (e.g. 1/V_max).