EF-hand calcium-binding protein (EF-hand)

EF-hand calcium-binding proteins are a large superfamily of proteins defined by a conserved helix-loop-helix structural motif that binds calcium ions with high affinity (UniProt, 2023). These proteins serve two primary roles: as calcium sensors that translate calcium signals into cellular responses through conformational changes, and as calcium buffers that regulate intracellular calcium levels (PubMed, 2021). Key members such as calmodulin, troponin C, and the S100 family are essential for diverse biological processes including muscle contraction, signal transduction, and cell cycle progression (NCBI, 2022). In clinical contexts, EF-hand proteins are significant; for instance, S100 proteins are frequently overexpressed in inflammatory diseases and various cancers, where they contribute to tumor progression and metastasis (PubMed, 2020). Troponins are critical diagnostic biomarkers for myocardial infarction, reflecting their central role in cardiac muscle regulation (StatPearls, 2023). Pharmacological targeting of these proteins involves small molecules like trifluoperazine or cromolyn that disrupt protein-protein interactions, though the ubiquity of EF-hand motifs across the proteome presents a major challenge for drug specificity (PubChem, 2023).

Other names

Calcium-binding proteinEF-hand domain-containing proteinCaBP

Binding of calcium ions to the EF-hand motif induces a conformational change that exposes a hydrophobic patch, allowing the protein to interact with and modulate the activity of various target enzymes and signaling proteins.