Grancalcin is calcium-binding protein which is particularly abundant in human neutrophils. GCA is a member of the penta EF-hand （PEF） subfamily of EF-hand proteins， who also comprises calpain， sorcin， peflin， and ALG-2. GCA undergoes essential conformational changes upon binding of calcium， which subsequently exposes hydrophobic amino acid residues， that direct the protein to hydrophobic surfaces. GCA cooperates with L-plastin， a protein known to have actin bundling activity， which suggests that GCA has a part in the regulation of neutrophils adhesion.
