Table 2.

Concentrations of selected substances able to inhibit by 50% the activity of Oryza sativa P5C synthetase 2.

	IC50 (mM)	Lower limit (mM)	Upper limit (mM)
L-proline	2.91	2.76	3.08
azetidine-2-carboxylic acid	11.0	10.2	11.9
phosphonoproline	42.2	37.8	47.3
L-4-hydroxyproline	89.5	76.4	105
NADP+	0.389	0.365	0.414
ADP	9.06	8.40	9.77
ornithine	52.6	48.4	57.2
arginine	63.9	58.0	70.3
glutamine	89.7	83.7	96.2
Mg++	34.8	27.6	46.4
Ca++	4.09	3.60	4.63

Confidence intervals (p=0.05) are also reported.