AQP4-M1 Full-Length Membrane Protein Products

Aquaporin-4 (AQP4) is a major water channel in the central nervous system, highly enriched in astrocytes and particularly at perivascular astrocyte endfeet. It contributes to brain water homeostasis, cell-volume regulation, and cerebrospinal fluid–interstitial fluid exchange. AQP4 is predominantly expressed as two major isoforms, M1 and M23. AQP4-M1 initiates translation at Met1 and contains 22 additional N-terminal amino acids compared with M23. Both isoforms assemble into functional water-conducting tetramers, but differ substantially in higher-order organization. M1 is less prone than M23 to form large orthogonal arrays of particles (OAPs) and can co-assemble with M23 to regulate OAP size and membrane organization.

These properties make AQP4-M1 particularly useful for investigating AQP4 tetramer structure, M1/M23 isoform differences, OAP regulation, and conformation-dependent antibody recognition. Notably, a 2025 cryo-EM study reconstituted full-length human AQP4-M1 into lipid nanodiscs to resolve the AQP4 tetramer and patient-derived NMOSD autoantibody complexes, highlighting the importance of studying full-length AQP4 in a membrane-like environment. AQP4 is implicated in cerebral edema, AQP4-IgG-positive neuromyelitis optica spectrum disorder (NMOSD), and neurodegenerative disease. Direct AQP4-targeted drug development remains relatively early, with the representative inhibitor AER-271 having completed Phase I evaluation. Explore the latest progress of AQP4-targeted drugs…

DIMA BIOTECH provides full-length human AQP4-M1 Nanodisc proteins in Synthetic Nanodisc, PeptiNanodisc, and biotinylated formats. These options support antibody screening, M1/M23 isoform comparison, binding characterization, cell-based assays, and AQP4 drug discovery.