HSPA5 Human, Hi-5

Heat shock 70kDa protein 5 (HSPA5), also known as Binding Immunoglobulin Protein (BiP) or Glucose-Regulated Protein 78 (GRP78), is a member of the heat shock protein 70 (HSP70) family. This protein plays a crucial role in the endoplasmic reticulum (ER) where it assists in the proper folding and assembly of proteins, maintaining ER homeostasis, and preventing apoptosis .

HSPA5 is a stress response protein induced by conditions that adversely affect ER function. It is a single, glycosylated polypeptide chain containing 640 amino acids and has a molecular mass of approximately 71 kDa . The protein is characterized by its ability to bind to misfolded proteins, preventing their aggregation and facilitating their proper folding.

The recombinant form of HSPA5, produced in Hi-5 cells, is tagged with a His-tag at the C-terminus to facilitate purification. The recombinant protein is typically purified using proprietary chromatographic techniques to achieve a purity greater than 90% as determined by SDS-PAGE . The recombinant HSPA5 is available in a liquid form, stored in a buffer containing Tris-HCl, glycerol, DTT, and NaCl to maintain its stability .

HSPA5 is essential for various cellular processes, including:

• Protein Folding and Assembly: It assists in the folding of newly synthesized proteins and the assembly of multi-protein complexes in the ER.
• ER Homeostasis: HSPA5 is a master regulator of ER homeostasis, ensuring the proper functioning of the ER under stress conditions .
• Prevention of Apoptosis: By maintaining protein homeostasis, HSPA5 helps prevent apoptosis, thereby contributing to cell survival under stress conditions .

Recombinant HSPA5 is widely used in research to study protein folding, ER stress responses, and the mechanisms of diseases related to protein misfolding. It is also utilized in the development of therapeutic strategies targeting ER stress-related diseases.