BPS2026 – Isolating low-expression level integral membrane proteins in plasma membrane-derived vesicles for structural studies

One of the remaining challenges in structural biology is capturing the structure of proteins in their native environment. This is particularly important for integral membrane proteins (IMPs) as their structural determination normally requires the use of membrane mimetics that remove IMPs from their native environment. We recently published a method to purify IMPs using plasma membrane vesicles, which better resemble in-vivo conditions than mainstream membrane mimetics. However, this method is currently limited to IMPs with high-expression levels. Here, we applied this method to an IMP (metabotropic glutamate receptor 6, mGluR6) with low-expression level. Using cryogenic electron microscopy, we were able to identify 2D classes that clearly demonstrate features consistent with metabotropic glutamate receptors. In the future, we will improve our method to further improve sample quality for IMPs with low-expression levels.