CALIXAR has applied the same approach used for the A2AR to other GPCRs such as the melatonin receptor (MT1). Melatonin receptor is an important target because it is a GPCR that modulates neuronal firing, arterial vasoconstriction, cell proliferation in cancer cells, and reproductive and metabolic functions. It is thus a good therapeutic candidate for insomnia, circadian sleep disorders, depression, cardiovascular regulation, cancer and neurodegenerative diseases. We have expressed the protein in Sf9 and yeast. The secondary structure prediction of the protein is shown in the following picture
After solubilization using a calixarene based detergent and purification, we could see by Electron microscopy that we had different isolated and non-aggregated particles even at very high protein concentration. This was also confirmed by size exclusion chromatography and Native PAGE.
We could also evaluate by Thermal Shift Assay that the protein was very stable for a GPCR. (Tm ~ 62°C).
MT1 was able to bind specifically in a radio-ligand binding assay and show a specific activation in protein G activation assay. As other GPCRs solubilized, purified and stabilized using our technology/ methodology, MT1 is a good candidate for drug discovery.
Off-the-shelf functional and pure MT1 protein produced as described above is now available for sale in our catalogue.
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