GCA Human

Grancalcin contains four EF-hand domains, which are helix-loop-helix structural motifs capable of binding calcium ions. The protein undergoes significant conformational changes upon binding calcium, exposing hydrophobic amino acid residues that direct the protein to hydrophobic surfaces . This property is crucial for its role in cellular processes.

The localization of grancalcin is dependent on the presence of divalent cations such as calcium and magnesium. In the absence of these cations, grancalcin is found in the cytosolic fraction. With magnesium alone, it partitions with the granule fraction, and in the presence of both magnesium and calcium, it associates with both the granule and membrane fractions . This suggests that grancalcin plays a role in granule-membrane fusion and degranulation, processes essential for the immune response.

Grancalcin is highly expressed in bone marrow and can be detected in neutrophils and macrophages . It is also expressed in other tissues such as the spleen, lung, and spinal ganglion .

Recombinant human grancalcin is produced using Escherichia coli expression systems. The recombinant protein typically includes a His-tag at the N-terminus to facilitate purification. The protein is purified using conventional chromatography techniques and is available in various formulations for research purposes .

Recombinant grancalcin is used in various research applications to study its role in calcium signaling, immune response, and cellular adhesion. It interacts with proteins such as L-plastin, which has actin-bundling activity, suggesting a role in the regulation of neutrophil adhesion .