TABLE 3.

[³H]Folic acid influx kinetic parameters in R1-11 cells transiently transfected with C-HA-WT-PCFT, C-HA-H247A, or C-HA-S172A mutants

Influx was assessed at pH 5.5 and 37 °C over 1 min. Data are the mean ± S.E. from three independent experiments.

	kt	Vmax
	μm	pmol/mg/min
C-HA-WT	0.69 ± 0.09	123.2 ± 4.5
C-HA-S247A	0.067 ± 0.004	7.6 ± 0.6
C-HA-S172A	0.19 ± 0.02	55.7 ± 1.2