Table 1. Study of kinetic properties of adenylyl cyclase activity of purified sperm membrane fraction.
| Assay system | Adenylyl cyclase activity | % mean of activity |
| (cAMP in pmole/mg/min) | ||
| Complete | 37±1.69 | 100 |
| −Mg++ | 3.8±0.27 | 10.2 |
| +EDTA (2 mM) | 0.94±0.07 | 2.5 |
| −Mg+++Ca++ (1 mM) | 3.9±0.1 | 10.5 |
| −Mg+++Ni++ (0.1 mM) | 3.89±0.14 | 10.5 |
| −ATP | 1.15±0.22 | 3.1 |
| −PCr | 31±3.21 | 83.7 |
| −F− | 35.9±2.23 | 97 |
| ddAdo (225 µM) | 9.1±0.8 | 24.6 |
| +Forskolin (0.1 mM) | 56.4±0.8 | 152.4 |
| + ddAdo+Forskolin | 12.4±1.77 | 33.5 |
| KH7 (25 µM) | 35.4±1.57 | 95.6 |
| +HCO3 − (50 mM) | 35.9±2.25 | 97 |
‘Complete’ assay medium for membrane protein AC-activity contains the following: 50 mM Tris-Cl, pH 8.5, 2 mM MgCl2, 0.5 mM NaF, 0.5 mM phosphocreatinine, 1.5 mM ATP-Na2. Results represent mean ± SEM for n = 5 experiments.