Grp78/BiP ELISA kit

• High throughput format with results for up to 40 samples in duplicate in just 2.5 hours
• Highly sensitive, reliably measuring 8.4ng/ml of GRP78/BiP
• Fully quantitative results surpass semi-quantitative Western blot analysis
• Easy-to-use and simplified protocol with less steps compared to sandwich assay formats

The GRP78/BiP ELISA kit is a colorimetric, competitive immunoassay kit with results in 2.5 hours.

Glucose-regulated protein (GRP78) also known as binding immunoglobulin protein or BiP, is a resident molecular chaperone of the ER involved in the folding and assembly of proteins, transport of newly synthesized polypeptides across the ER membrane, regulation of calcium homeostasis and targeting misfolded proteins for degradation. GRP78 also regulates the transmembrane proteins, PERK, IRE1 and ATF6 by binding the N-terminal domains in the lumen of the ER preventing these signal transducers from initiating the unfolded protein response (UPR), an adaptive response to changes in the intracellular environment meant to restore normal ER function.
When protein misfolding occurs, exposed hydrophobic residues on the protein are bound by GRP78 preventing protein aggregation, further transit, and secretion. Intracellular stress such as glucose deprivation and viral infection can lead to a rapid accumulation of unfolded proteins. As unfolded proteins accumulate, more available GRP78 is required to bind the hydrophobic regions causing it to dissociate from the transmembrane signaling proteins thus initiating the UPR. After dissociation from GRP78, activated PERK attenuates general translation to prevent further protein synthesis, ATF6 and IRE1 upregulate the production of ER folding and chaperone proteins including GRP78, and proteins that promote degradation of misfolded proteins through ER-associated protein degradation (ERAD). The overexpression of GRP78 as a result of UPR activation is believed to contribute to the pathology of metabolic disease, inflammatory disease, neurodegenerative disorders, and cancer.