TABLE 2.

Substrate inhibition of phthalate uptake

Competing substrate	% Inhibition of phthalate uptakea
	E. coli (OphD)b	HK638 (OphD+ OphF− OphP+)	HK405 (OphD− OphF+ OphP+)
Phthalate	91 ± 1	>95	>95
4-Hydroxyphthalate	86 ± 2	>95	34 ± 13
4-Chlorophthalate	66 ± 4	>95	>95
4-Methylphthalate	32 ± 4	31 ± 7	<5
Quinolinate	<10	20 ± 7	<5
Cinchomeronate	27 ± 6	28 ± 9	<5
Salicylate	<10	51 ± 7	>95

^aInhibition of phthalate uptake was calculated as follows: % inhibition = [100 − (¹⁴C-labeled phthalate transport rate with competing substrate/¹⁴C-labeled phthalate transport rate without competing substrate)] × 100. The concentrations of ¹⁴C-labeled phthalate and competing substrate used were 50 μM and 1 mM, respectively (3).

^bData from reference 3.