Table 1.
Ca2+ binding properties of centrins.
| Organism | Centrin | UniProt Code | Experimental Ca2+-Binding Sites a |
Ca2+ Affinity b | Refs |
|---|---|---|---|---|---|
| Chlamydomonas reinhardtii | CrCEN | P05434 | 4 | Kd1,2N = 1.2 ± 0.1 × 10−6 M Kd3C = 2 ± 2 × 10−5 M Kd4C = 3 ± 2 × 10−3 M |
[64,65,66] |
| Scherffelia dubia | SdCEN | Q06827 | 3 | Ka1N = 2.6 × 105 M−1 Ka2N = 4.3 × 105 M−1 Ka3C = 1.1 × 105 M−1 |
[52] |
| Homo sapiens | HsCEN1 | Q12798 | 4 | Ka1,2 = 4.26 × 105 ± 9.5 × 104 M−1 Ka3,4 = 2.73 × 104 ± 2.7 × 103 M−1 |
[67,68] |
| Homo sapiens | HsCEN2 | P41208 | 2 | Ka(EF-3) = 8.1 × 103 M−1 Ka(EF-4) = 1.5 × 105 M−1 |
[43,48,49,50,62] |
| Homo sapiens | HsCEN3 | O15182 | 3 | Ka1N = 3.3 × 105 M−1 Ka2 = 7.0 × 103 M−1 Ka3 = 7.5 × 103 M−1 |
[69] |
| Saccharomyces cerevisiae | CDC31 | P06704 | 3 | Ka(EF-1) = 3.0 × 106 M−1 Ka2C = 2.4 × 104 M−1 Ka3C = 3.5 × 104 M−1 |
[19,70] |
| Mus musculus | MmCEN1 | P41209 | 4 | Ka1 = 5.23 × 105 M−1 Ka2 = 3.11 × 103 M−1 Ka3 = 2.31 × 105 M−1 Ka4 = 1.59 × 104 M−1 |
[51] |
| Arabidopsis thaliana | AtCEN2 | O23184 | 4 | Ka(EF-1) = 2.9 × 105 ± 7.1 × 104 M−1 Ka(EF-2) = 4.1 × 105 ± 6.8 × 104 M−1 Ka(EF-3) = 1.4 × 104 ± 3.8 × 103 M−1 Ka(EF-4) = 3.7 × 103 ± 0.8 × 103 M−1 |
[22] |
| Toxoplasma gondii | TgCEN1 | A0A125YHX7 | 2 | Ka(EF-1) = 4.8 × 105 ± 6.1 × 103 M−1 Ka(EF-2) = 3.9 × 104 ± 4.5 × 103 M−1 |
[53] |
| Toxoplasma gondii | TgCEN2 | A0A125YZN2 | 1 | Ka(EF-1) = 1.6 × 104 ± 1.5 × 103 M−1 | [53] |
| Trypanosoma brucei | TbCEN4 | A0A3L6L623 | 2 | Ka(EF-3) = 3.18 × 105 ± 4.63 × 104 M−1 Ka(EF-4) = 2.63 × 104 ± 4.37 × 103 M−1 |
[14] |
| Trypanosoma brucei | TbCEN5 | Q382E7 | 2 | Kd1,2 = 4.8 µM | [71] |
| Euplotes octocarinatus | EoCEN | Q9XZV2 | 4 | Ka1,2 = 1.12 ± 0.04 × 103 M−1 Ka(EF-4) = 6.82 ± 0.33 × 105 M−1 |
[13,72] |
| Blastocladiella emersonii | BeCEN1 | Q4F6W6 | 4 | Kd1 = 6.06 ± 2.26 µM Kd2 = 7.50 ± 0.44 µM Kd3 = 75.20 ± 28.3 µM Kd4 = 9.35 ± 0.93 µM |
[73] |
| Blastocladiella emersonii | BeCEN3 | Q4F6W5 | 4 | Kd1 = 2.45 ± 0.04 µM Kd2 = 18.50 ± 0.86 µM Kd3 = 2.11 ± 0.38 µM Kd4 = 38.1 ± 7.46 µM |
[73] |
a Number of functional Ca2+-binding sites as experimentally measured by isothermal titration calorimetry (ITC), nuclear magnetic resonance (NMR) or flow dialysis analysis. b Ka = equilibrium association constant; Kd = dissociation constant. Kd is the inverse of the equilibrium association constant, Ka, (i.e., Kd = 1/Ka). N = N-terminal domain. C = C-terminal domain. Where the EF-hand site is not specified, binding affinities refer to the affinity for the first, second, third and fourth Ca2+ bound, not to the affinity of the individual sites.