Calreticulin (human, recombinant)

Calreticulin is a calcium-binding protein involved in intracellular calcium storage and glycoprotein folding, among other processes.1,2 It is composed of an N-terminal globular N domain, a proline-rich P domain containing a high-affinity, low-capacity calcium-binding site, an acidic C domain containing a low-affinity, high-capacity calcium-binding site, and a C-terminal endoplasmic reticulum retention sequence.3 Calreticulin is widely expressed and localizes primarily to the lumen of the endoplasmic or sarcoplasmic reticulum in non-muscle or muscle cells, respectively, but is also found at the cell surface, in the extracellular matrix, and in the cytoplasm.3,4,1 It has a high calcium-binding capacity and is involved in the regulation of intracellular calcium homeostasis, which makes it an integral factor in many calcium-related processes, such as muscle contraction and the cellular stress response.3,4 Calreticulin also acts as a chaperone for newly synthesized glycoproteins in conjunction with protein disulfide-isomerase A3, also known as ERp57, and calnexin in the calreticulin/calnexin cycle to ensure proper glycoprotein folding.1 Insertion or deletion mutations in exon 9 of CALR, the gene encoding calreticulin, are found in a subset of patients with essential thrombocythemia or primary myelofibrosis and are associated with increased overall survival and a lower risk of thrombosis.{ 67991} Cayman's Calreticulin (human, recombinant) protein consists of 396 amino acids, has a calculated molecular weight of 45.99 kDa, and a predicted N-terminus of Glu18 after signal peptide cleavage. WARNING This product is not for human or veterinary use. Purity: >90% as determined by SDS-PAGE. Endotoxin Testing: <1.0 EU/µg determined by the LAL endotoxin assay. Source: Recombinant human calreticulin expressed in HEK293 cells. Amino Acids: 18-413. MW: 45.99 kDa. Formulation: Lyophilized from sterile PBS, pH 7.4.