@article {Trinh2022.01.10.475744, author = {Thi Kim Hoang Trinh and Claudio Catalano and Youzhong Guo}, title = {Membrane-active Polymers: NCMNP13-x, NCMNP21-x and NCMNP21b-x for Membrane Protein Structural Biology}, elocation-id = {2022.01.10.475744}, year = {2022}, doi = {10.1101/2022.01.10.475744}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Membrane proteins are a ubiquitous group of bio-macromolecules responsible for many crucial biological processes and serve as drug targets for a wide range of modern drugs. Detergent-free technologies such as styrene-maleic acid lipid particles (SMALP), diisobutylene-maleic acid lipid particles (DIBMALP), and native cell membrane nanoparticles (NCMN) systems have recently emerged as revolutionary alternatives to the traditional detergent-based approaches for membrane protein research. NCMN systems aim to create a membrane-active polymer library suitable for high-resolution structure determination. Herein, we report our design, synthesis, characterization and comparative application analyses of three novel classes of NCMN polymers, NCMNP13-x, NCMNP21-x and NCMNP21b-x. Although each NCMN polymer can solubilize various model membrane proteins and conserve native lipids into NCMN particles, only the NCMNP21b-x series reveals lipid-protein particles with good buffer compatibility and high homogeneity suitable for single-particle cryo-EM analysis. Consequently, the NCMNP21b-x polymers that bring out high-quality NCMN particles are particularly attractive for membrane protein structural biology.HighlightsDemonstrate straightforward strategies for tailoring styrene-maleic co-polymer (SMA) that revealed novel buffer compatible polymers, NCMNP13-50, NCMNP21-20 and NCMNP21b-x.Elucidate how modification factors alter the membrane-active properties of these polymers, i.e., membrane protein extraction efficiency, morphology, etc.Provide valuable insights into the rational design of membrane-active polymers for membrane protein structural biology.NCMNP21b-x polymers are highly compatible with high-resolution structure determination using an emerging technique, cryo-EM.Competing Interest StatementY.G. and T.K.H.T are inventors of NCMNP13-50, NCMNP21-20 and NCMNP21b-x patents}, URL = {https://www.biorxiv.org/content/early/2022/01/11/2022.01.10.475744}, eprint = {https://www.biorxiv.org/content/early/2022/01/11/2022.01.10.475744.full.pdf}, journal = {bioRxiv} }