HSPA5/GRP-78 Protein, Human (His)

HSPA5/GRP-78 is an endoplasmic reticulum chaperone that coordinates protein folding and quality control. It cooperates with DNAJC10/ERdj5 to facilitate correct protein folding and participates in the degradation of misfolded proteins, potentially releasing DNAJC10/ERdj5. HSPA5/GRP-78 Protein, Human (His) is the recombinant human-derived HSPA5/GRP-78 protein, expressed by E. coli , with N-6*His labeled tag.

HSPA5/GRP-78, an endoplasmic reticulum chaperone, assumes a pivotal role in orchestrating protein folding and quality control within the endoplasmic reticulum lumen. Partnering with DNAJC10/ERdj5, it contributes to the proper folding of proteins and participates in the degradation of misfolded counterparts, potentially facilitating the release of DNAJC10/ERdj5 from its substrate. Functioning as a critical suppressor of the unfolded protein response (UPR) mediated by ERN1/IRE1, HSPA5/GRP-78 is recruited to the luminal region of ERN1/IRE1 by DNAJB9/ERdj4 under unstressed conditions, disrupting ERN1/IRE1 dimerization and thereby inactivating ERN1/IRE1. However, the accumulation of misfolded proteins prompts the release of HSPA5/BiP from ERN1/IRE1, allowing for homodimerization and subsequent activation of ERN1/IRE1. Additionally, HSPA5/GRP-78 serves as an auxiliary player in the post-translational transport of small presecretory proteins across the endoplasmic reticulum and is implicated in apoptosis, cell proliferation, and viral infection, acting as a cellular receptor for several flaviviruses, including Dengue virus, Zika virus, and Japanese encephalitis virus.

1. HSPA5 has ATPase activity at the time of manufacture of 35.972 µM phosphate liberated/hr/µg protein in a 200 µL reaction at 37°C (pH7.5) in the presence of 10 μL of 4 mM ATP, using a Malachite Green assay.
2. HSPA5 has ATPase activity at the time of manufacture of 13.779 µM phosphate liberated/hr/µg protein in a 240 µL reaction at 37°C (pH7.5) in the presence of 10 µL of 4 mM ATP, using a Malachite Green assay.

Human

E. coli

N-6*His

P11021 (E25-E293)

3309  [NCBI]

Partial

EDVGTVVGIDLGTTYSCVGVFKNGRVEIIANDQGNRITPSYVAFTPEGERLIGDAAKNQLTSNPENTVFDAKRLIGRTWNDPSVQQDIKFLPFKVVEKKTKPYIQVDIGGGQTKTFAPEEISAMVLTKMKETAEAYLGKKVTHAVVTVPAYFNDAQRQATKDAGTIAGLNVMRIINEPTAAAIAYGLDKREGEKNILVFDLGGGTFDVSLLTIDNGVFEVVATNGDTHLGGEDFDQRVMEHFIKLYKKKTGKDVRKDNRAVQKLRREVE

Approximately 33 kDa, based on SDS-PAGE under reducing conditions.

• 
  Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized from a 0.22 μm solution of PBS, 6% Trehalose, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.