Table 1. Ca2+ binding properties of CaM and CB.
CaM measurements were made on wild-type (WT) and Ca2+-binding site mutant CaMs (EF3,4 and EF1,2) in which only one lobe is functional. Constants are listed in parentheses and as log values ± S.D. above.
| N terminus | C terminus | CB | ||||
|---|---|---|---|---|---|---|
| CaMWT (high Kd(app)) | CaMEF34 | CaMWT (low Kd(app)) | CaMEF12 | |||
| n | conditions | 7 | 4 | 7 | 4 | 10 |
| traces | 94 | 52 | 94 | 51 | 150 | |
| n (fitsets) | 32 | 26 | 32 | 30 | 30 | |
| Kd(T) | log M (μM) | −3.7±0.3 (193) | −3.1±0.6 (641) | −4.6±0.2 (27.8) | −4.1±0.4 (86.9) | −6.4±0.2 (0.393) |
| Kd(R) | log M (μM) | −6.1±0.3 (0.788) | −6.8±0.6 (0.138) | −6.6±0.3 (0.264) | −6.5±0.3 (0.261) | |
| Kd(app) | log M (μM) | −4.9±0.1 (12.7) | −5.0±0.0 (9.2) | −5.6±0.2 (2.7) | −5.3±0.1 (4.8) | |
| nH | 1.9±0.1 | 2.0±0.0 | 1.8±0.1 | 1.9±0.1 | ||
| kon(T) | log M−1s−1 (M−1s−1) | 8.9±0.3 (7.7×108) | 8.8±0.4 (7.0×108) | 7.9±0.3 (8.4×107) | 8.1±0.4 (1.2×108) | 7.9±0.1 (7.5×107) |
| kon(R) | log M−1s−1 (M−1s−1) | 10.5±0.6 (3.2×1010) | 10.0±0.6 (1.1×1010) | 7.4±0.1 (2.5×107) | 7.5±0.1 (3.3×107) | |
| koff(T) | log s−1 (s−1) | 5.2±0.5 (1.6×105) | 5.7±0.7 (5.2×105) | 3.4±0.4 (2.6×103) | 3.9±0.7 (8.7×103) | 1.5±0.2 (29.5) |
| koff(R) | log M−1s−1 (s−1) | 4.3±0.6 (2.2×104) | 3.2±0.1 (1.5×103) | 1.2±0.3 (6.5) | 1.0±0.2 (9.6) | |