... 90% of the change in the a helix content was attained by binding of two Ca21 Interestingly, in the mutants which have only three Ca21-binding sites, the binding of two Ca21 was sufficient to induce ... conformational changes induced by the second Ca21-binding increase the affinity of EF-C to induce the third Ca21-binding (c) Finally, the fourth Ca21-binding takes place at EF-D with high affinity Although ... constants obtained were slightly larger than those obtained in S100 dimers [16] This is because in the study in Fig 1, The antagonistic effect of K1 on Ca21-binding was observed in many of Ca21-binding...