Table 1.

Activity measurement of 92 agonists on the cCaSR: All compounds listed here were screened using the HEK T-Rex/ natClytin cell line inducibly expressing cCaSR in an agonist assay. All measurements were repeated over at least three wells on the same assay plate. If the maximal response to a compound was not reached, the EC₅₀ value could not be determined and is expressed as an estimation at > 0.01 M. For all agonists, the activity on cCaSR is described in a separate column: + : EC50 equal or above to 0.1 M, ++: EC50 below 0.1, +++: EC50 below 0.001. The compounds are grouped by different classes. 1–7: Cations, 8–39: Amino acids and derivatives, 40–42: Polybasic peptides, 43–47: GSH and derivatives, 48–50: Biogenic amines, 51–54: β-aspartyl peptides, 55–73: γ-glutamyl peptides, 74–80: Aminoglycoside antibiotics, 81–84: Sugars and derivatives, 85: 1,4,8,11-tetraazacyclotetradecane, 86–92: Organic acids.

No	Compound	cCaSR activity	EC50 (M)	No	Compound	cCaSR activity	EC50 (M)	No	Compound	cCaSR activity	EC50 (M)	No	Compound	cCaSR activity	EC50 (M)
1	Ba2+	++	0.001172	24	γ-Carboxy-DL-glutamic acid	+	> 0.01	47	S-Methylglutathione	++	0.00442	70	γ-D-Glu-Trp	+  +	0.0042
2	Ca2+	++	0.00162	25	L-Glutamine	−	−	48	Cadaverine	−	–	71	γ-Glu-Cys-Gly-Oet	−	–
3	Gd3+	+++	0.000295	26	L-Isoglutamine	+	> 0.01	49	Spermidine	++	0.00249	72	γ-Glu-Val-Gly	+  +	0.00422
4	Mg2+	+	> 0.01	27	Glycine	−	−	50	Spermine	+	> 0.01	73	γ-Glu-ε-Lys	−	–
5	Pr3+	+++	0.000398	28	L-Isoleucine	−	−	51	β-Asp-Ala	+	> 0.01	74	Geneticin	+	> 0.01
6	Sr2+	+	> 0.01	29	L-Leucine	−	−	52	β-Asp-Gly	+	> 0.01	75	Gentamicin	+  +  +	0.000989
7	Tb3+	+++	0.000175	30	L-Methionine	−	−	53	β-Asp-Leu	+	0.00315	76	Hygromycin B (Streptomyces hygroscopicus)	−	–
8	L-Alanine	−	–	31	L-Proline	−	−	54	β-Asp-Phe	+	> 0.01	77	Neomycin	+  +	0.00187
9	L-Asparagine	−	–	32	L-Serine	−	−	55	γ-Glu-Abu-Gly	++	0.00265	78	Paromomycin sulfate salt	+  +	0.00108
10	L-Aspartic acid	++	0.00411	33	L-Threonine	−	−	56	γ-Glu-Abu	+	> 0.01	79	Ribostamycin sulfate salt	+	> 0.01
11	D-Aspartic Acid	−	–	34	L-Tyrosine	−	−	57	γ-Glu-Ala	+	> 0.01	80	Sisomicin sulfate salt	+  +  +	0.000299
12	L-Aspartic acid β-methyl ester hydrochloride	+	> 0.01	35	O-Phospho-L-tyrosine	+	> 0.01	58	γ-Glu-Cys	+	> 0.01	81	3-O-Methyl-D-glucopyranose	−	–
13	DL-Aspartic acid α-methyl ester	+	> 0.01	36	L-Valine	−	−	59	γ-Glu-Gln	+	> 0.01	82	D-( +)-Glucose	−	–
14	(S)-a-Methylaspartic acid	−	–	37	L-Histidine	−	−	60	γ-Glu-Glu	++	0.00207	83	Sucralose	−	–
15	L-Cysteine	−	–	38	Taurine	−	−	61	γ-Glu-Glu-Gln	+	> 0.01	84	Sucrose	−	–
16	Cystine (disufide)	−	–	39	L-Ornithine	−	−	62	γ-Glu-Glu-Glu	++	0.00235	85	1,4,8,11-tetraazacyclotetradecane	+  +  +	0.000773
17	Se-(Methyl)selenocysteine	++	0.00447	40	Poly-L-arginine	+++	1.014 E-06	63	γ-Glu-Gly	+	> 0.01	86	1 s,3 s-1-aminocyclobutane-1,3-dicarboxylic acid	+	> 0.01
18	L-Cysteic acid monohydrate	++	0.00234	41	Poly-L-lysine	+	> 0.01	64	γ-Glu-Leu	+	> 0.01	87	2-Amino-4-phosphonobutyric acid	+	> 0.01
19	L-Homocysteic acid	+	> 0.01	42	Poly-L-ornithine	+++	0.00023	65	γ-Glu-Met	+	> 0.01	88	2-Aminopimelic acid	+	> 0.01
20	L-Glutamic acid	+	> 0.01	43	Glutathione	++	0.00639	66	γ-Glu-Phe	++	0.00232	89	L-( +)-2-Amino-3-phosphonopropionic acid	+	> 0.01
21	D-Glutamic acid	−	–	44	3-Glutathionyl-S-methylindole	++	0.00374	67	γ-Glu-Trp	+	> 0.01	90	L-2-Aminoadipic acid	+	> 0.01
22	4-Fluoro-DL-glutamic acid	+	> 0.01	45	S-(2-Hydroxyethyl)glutathione	++	0.00211	68	γ-Glu-Tyr	++	0.00388	91	Methylenediphosphonic acid	+  +	0.00129
23	2S,4S-g-Hydroxy-L-glutamic acid	+	> 0.01	46	S-Lactoylglutathione	+	> 0.01	69	γ-Glu-Val	++	0.00452	92	Methylphosphonic acid	+	> 0.01