Table 4.

Distance between two carboxyl-groups on l-aspartate analogs.

No.	Compounds	KD (M)	NCarbon	†NNH2	R (Å)	Sensitivity
14	l-Aspartate	6.E−08	2	1	2.950	7.2
35	dl-α-Methylaspartate	5.E−07	2	1	2.958	6.3
36	dl-β-Methylaspartate	3.E−04	2	1	2.991	3.5
44	Oxaloacetate		2		3.002
37	N-Methyl-dl-aspartate	1.E−03	2		3.006	3.0
13	d-Aspartate	1.E−05	2	1	3.084	5.0
33	l-Malate	6.E−04	2		3.151	3.2
27	dl-Threo-β-hydroxyaspartate	1.E−04	2	1	3.218	4.0
53	l-Glutamate	5.E−06	3	1	3.269	5.3
2	N-Acetyl-l-aspartate	1.E−03	2		3.282	3.0
22	Fumarate	3.E−04	2		3.764	3.5
42	2-Methylsuccinate	5.E−03	2		3.803	2.3
52	Succinate	2.E−04	2		3.820	3.7
26	dl-Erythro-β-hydroxyaspartate	5.E−04	2	1	3.861	3.3
38	dl-α-Methylglutamate		3	1	4.444
31	α-Ketoglutarate		3		5.063
5	l-α-Aminoadipate		4	1	6.358

The 17 compounds were arranged in ascending order of the distance between their carboxyl groups (R). The –NHR of the amino group was excluded from the count.

^aNumber of –NH₂ groups.