Advances in nanodisc platforms for membrane protein purification

Membrane scaffold protein nanodiscs (MSPNDs) are an invaluable tool for improving purified membrane protein (MP) stability and activity compared to traditional micellar methods, thus enabling an increase in high-resolution MP structures, particularly in concert with cryogenic electron microscopy (cryo-EM) approaches. In this review we highlight recent advances and breakthroughs in MSPND methodology and applications. We also introduce and discuss saposin-lipoprotein nanoparticles (salipros) and copolymer nanodiscs which have recently emerged as authentic MSPND alternatives. We compare the advantages and disadvantages of MSPNDs, salipros, and copolymer nanodisc technologies to highlight potential opportunities for using each platform for MP purification and characterization.