Table 2.
Heparin and IP3 binding to N-terminal fragments of IP3 receptor subtypes
| NT1 | NT2 | NT3 | IP3R1 | |
|---|---|---|---|---|
| IP3 | 7.76 ± 0.07 | 8.67 ± 0.15 | 7.39 ± 0.08 | 7.13 ± 0.08 |
| Heparin | 7.42 ± 0.09 | 7.95 ± 0.32 | 6.59 ± 0.09* | 5.61 ± 0.13 |
Equilibrium-competition binding with 3H-IP3 was used to measure pKD values for IP3 (as M) and heparin (as g mL−1) binding to purified NT1-3 and cerebellar membranes (IP3R1). Results are means ± SEM from three to six experiments.
*
Denotes a significant difference from NT1 (P < 0.05) for 
.