TABLE 1.

Kinetic parameters determined from radiolabeled serotonin uptake and imipramine binding studies

HEK293 cells were transiently transfected with the plasmids encoding wild type hSERT or the N-terminal truncations thereof. After 48 h, specific 5-[³H]HT uptake was measured. [³H]Imipramine binding assays were carried out in membranes preparations (see “Experimental Procedures”). K_m, V_max, K_D, and B_max values were determined from data shown in Fig. 2, C and D. K_i values of p-CA or ibogaine were calculated from inhibition of [³H]imipramine binding data shown in Fig. 3, C and D. The values are represented as arithmetic means ± S.E. from at least two independent experiments performed in duplicate (binding) or triplicate (uptake). Different conditions were statistically compared by one-factor analysis of variance followed by Tukey's post hoc t tests.

Transporter	Vmax	Km	Bmax	KD	Turnover number	Ki p-CA	Ki ibogaine
	pmol/106cells min−1	μm	pmol/mg protein	nm	min−1	μm	μm
SERT-WT	182.1 ± 35.0	2.3 ± 0.6	10.1 ± 1.4	4.9 ± 2.0	186	1.9 ± 0.2	2.8 ± 0.5
SERT-ΔN22	181.3 ± 24.6	1.8 ± 0.7	8.6 ± 1.0	3.8 ± 1.4	195	2.2 ± 0.5	2.8 ± 0.8
SERT-ΔN32	203.4 ± 11.3	2.6 ± 1.5	8.0 ± 1.6	7.9 ± 4.0	239	2.3 ± 0.4	5.3 ± 1.3
SERT-ΔN42	86.8 ± 26.7a	2.6 ± 1.2	3.7 ± 0.5a	6.6 ± 2.3	257	2.9 ± 2.0	5.4 ± 0.6

^a p < 0.001, significantly different from control.