The chaperone proteins in our antibody catalog are of great interest to molecular biologists, as they assist in the non-covalent folding and assembly of other polypeptides into their correct functional form. We at Novus Biologicals have an extensive range of chaperone antibodies on our antibody database, including the heat shock protein Hsp90.
While many of the chaperone proteins covered by antibody suppliers assist in the folding of newly synthesised macromolecules, many others repair existing proteins which have undergone mismatched folding due to heat stress. Hsp90 belongs to this second group; however, research has shown it to have a number of other functions in non-stressed cells.
One of the most abundantly expressed cellular proteins, Hsp90 accounts for around 1 – 2% of the total protein content of eukaryotic cells under normal conditions. However, under heat stress, this figure can rise to 6%. First isolated during antibody assays investigating heat-induced protein denaturation, Hsp90 is now known to be critical to normal cell signaling, playing vital roles in protein biosynthesis and cell maintenance. It also aids protein degradation, stabilizing the 26S proteasome and associated kinases. In this way it aids apoptosis and represses tumor growth.
Dysregulation of Hsp90 is associated with an increased risk of carcinogenesis, and in its normal state can contribute to tumor growth through stabilizing proteins upregulated in cancer cells. These include the growth factor receptor EGFR, and the signal transducers PI3K and AKT. Hsp90 is also thought to protect unstable proteins arising from DNA mutations, such as v-Src, p53 and the fusion oncogene Bcr/Abl – all well represented in our antibody catalog. In addition, it aids induction of the angiogenesis factors VEGF and nitric oxide synthase (NOS), as well as promoting metastasis through interaction with MMP2.
In the last 10 years, the Hsp90 antibody database has played an important part in the development of Hsp90 inhibitors, some of which have reached the clinical trials stage.