Table 3.
EC50 values for Ca2+ release induced by NAADP (1) and NAADP analogs (16-24) measured fluorometrically from Ca2+ loaded sea urchin egg homogenates.
| Compound | EC50 ± s.d., nM (n) | Fold increase in EC50 |
|---|---|---|
| NAADP (1) | 18.7 ± 6.9 (19) | 1 |
| 5-amino-NAADP (20) | 27.4 ± 13.9 (9) | 1.5 |
| 5-methyl-NAADP (21) | 43.0 ± 25.3 (11) | 2.3 |
| 5-ethyl-NAADP (23) | 352 ± 219 (3) | 18 |
| 5-azido-NAADP (24) | 1689 ± 1349 (9) | 90 |
| 4-amino-NAADP (16) | 4413 ± 2794 (8) | 235 |
| 4-methyl-NAADP (17) | 42231 ± 28870 (6) | 2200 |
| 4-n-butyl-NAADP (18) | >1,000,000 (5) | > 50,000 |
| 4-phenyl-NAADP (19) | >1,000,000 (6) | > 50,000 |
| 5-carboxy-NAADP (22) | > 1,000,000 (3) | > 50,000 |