Utilizing native nanodiscs to isolate active TRPC3 channels and expand structural analysis capabilities

Recent advances in structural biology have provided insights into TRPC3, a TRP family member involved in various (patho)physiological processes. However, the lack of structural information on the channel's open pore hampers understanding of its function and therapeutic potential. Cryogenic electron microscopy holds promise for elucidating TRPC3's open-pore conformation, but challenges remain in isolating it without compromising function. Our study evaluated novel extraction agents in comparison to conventional detergents for isolating functional TRPC3 complexes from HEK293, Komagataella phaffii, and Expi293F cells, identifying Expi293F as optimal for TRPC3 expression. Among the extraction agents screened, dodecyl diglucoside (DDDG) and n-dodecyl-β-D-maltoside (DDM) were the most effective for extracting TRPC3. We successfully purified TRPC3 under native conditions, preserving its tetrameric structure and activity, as confirmed by electron microscopy, mass spectrometry and patch-clamp analysis. This study highlights the importance of extraction agents in advancing TRPC3 research and therapeutic development.