Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites.
Highly prevalent in heart. Also found in lesser quantities in skeletal muscle and brain.
Belongs to the S-100 family. Contains 2 EF-hand domains.