Table 3.

Stoichiometry of Na⁺-to-glucose transport

Mutant	Stoichiometry
Wild type	2.0 ± 0.05 (3)
L87C	2.3 ± 0.1 (3)
F101C	4.3 ± 0.2 (3)
F453C	5.9 ± 0.6 (6)
G507C	1.9 ± 0.06 (3)

Stoichiometry values (means ± SE) were obtained from the ratio of the αMDG-induced inward Na⁺ current (converted to moles) and the [¹⁴C]αMDG uptake in single oocytes expressing SGLT1. The external [¹⁴C]αMDG concentration was 0.2 to 1 mM in 100 mM NaCl buffer, and the membrane potential of the oocytes was clamped at −90 mV.