TABLE 2

Kinetic constants for copper and CDDP uptakes by SCLC and various mutant hCtr1-transfected cells

Data from copper and CDDP uptake experiments at various concentrations were analyzed using the Michaelis-Menten equation, 1/V = 1/V_max+ K_m/V_max · [S] (where [S] is the copper or cisplatin concentration). K_m values and V_max were derived from three experiments (experiments for each protein, each experiment consisting of triplicate determinations). S.E. for the K_m and V_max values are shown.

	Copper						Cisplatin
	K_m	K_mMutant/Vector	P	V_max	V_max Mutant/Vector	P	K_m	K_mMutant/Vector	P	V_max	V_max Mutant/Vector	P
	μM			pmol/mg protein/min			μM			pmol/mg protein/min
SCLC	4.86 ± 0.5	0.95		16.2 ± 1.4	1.05		13.1 ± 1.9	1.10		22.8 ± 1.9	1.02
vector	5.12 ± 0.4			15.4 ± 1.4			11.9 ± 1.5			22.4 ± 1.9
WT	5.42 ± 0.4	1.06		87.2 ± 9.5	5.66	<0.01	17.2 ± 2.6	1.45		117 ± 10	5.22	<0.01
M43-Q	3.54 ± 0.3	0.69	<0.01	5.24 ± 0.4	0.34	<0.01	11.1 ± 1.0	0.93		8.43 ± 1.3	0.38	<0.05
M45-Q	3.99 ± 0.3	0.78	<0.05	6.99 ± 0.5	0.45	<0.01	15.9 ± 1.0	1.34		8.47 ± 1.0	0.38	<0.05
M154-Q	3.55 ± 0.3	0.69	<0.01	5.02 ± 0.4	0.33	<0.01	12.2 ± 1.3	1.03		11.1 ± 0.5	0.50	<0.05
G167-S	3.78 ± 0.2	0.74	<0.05	6.26 ± 0.5	0.41	<0.01	6.82 ± 0.7	0.57	<0.05	16.9 ± 0.7	0.75
δN2-M154-Q	5.25 ± 0.4	1.03		15.5 ± 1.2	1.01		11.5 ± 1.1	0.97		21.8 ± 1.6	0.97
δN2-G167-S	4.99 ± 0.4	0.97		14.9 ± 1.1	0.97		13.7 ± 1.2	1.15		22.8 ± 0.9	1.02