Rockefeller University Press

Table III

Substrate Voltage Dependence Normalized to K_m at −100 mV

V (mV)	−80	−60	−40	−20	0
K_m^Na (0.1 mM P_i)	1.01	1.08	1.17	1.41	1.48
K_m^Na (1.0 mM P_i)	1.00	1.04	1.08	1.21	1.24
K_m^Pi (50 mM Na⁺)	1.14	1.57	2.08	2.41	3.68
K_m^Pi (96 mM Na⁺)	1.03	1.14	1.28	1.43	1.59

V (mV)	−80	−60	−40	−20	0
K_m^Na (0.1 mM P_i)	1.01	1.08	1.17	1.41	1.48
K_m^Na (1.0 mM P_i)	1.00	1.04	1.08	1.21	1.24
K_m^Pi (50 mM Na⁺)	1.14	1.57	2.08	2.41	3.68
K_m^Pi (96 mM Na⁺)	1.03	1.14	1.28	1.43	1.59

Data are taken from the absolute apparent affinity constant data for P_i binding and Na⁺ binding in Figs. 2,C and 3 C, respectively.