Macrodiscs Comprising SMALPs for Oriented Sample Solid-State NMR Spectroscopy of Membrane Proteins

Abstract

Macrodiscs, which are magnetically alignable lipid bilayer discs with diameters of >30 nm, were obtained by solubilizing protein-containing liposomes with styrene-maleic acid copolymers. Macrodiscs provide a detergent-free phospholipid bilayer environment for biophysical and functional studies of membrane proteins under physiological conditions. The narrow resonance linewidths observed from membrane proteins in styrene-maleic acid macrodiscs advance structure determination by oriented sample solid-state NMR spectroscopy.

Metal‐Chelated Polymer Nanodiscs for NMR Studies

“…Nanodiscs are comprised of a discoidal lipid bilayer stabilized by an amphiphilic belt comprised of either peptidic based or polymer based molecules . The introduction of amphiphilic polymers that form lipid nanodiscs has most notably contributed to the study of membrane proteins (MPs) and allows for their functional and structural study in a tunable native‐like membrane environment . While polymer nanodiscs are the youngest of the nanodisc field, they are showing great potential due to the simplicity of their synthesis, their diverse chemical tunability, and their ability to directly extract membrane proteins from their cellular environment at practical cost .…”

“…Nanodiscs are a useful tool for NMR spectroscopy since their size can be tuned to conditions favorable to both solution and solid‐state NMR. Additionally, nanodiscs were shown to align in the presence of the magnetic field which can provide additional useful structural information . Despite these advantages the fundamental challenges related to poor NMR sensitivity still remain, requiring long acquisition times and high sample concentrations .…”

“…[1][2][3][4] Thei ntroduction of amphiphilic polymers that form lipid nanodiscs has most notably contributed to the study of membrane proteins (MPs) and allows for their functional and structural study in at unable native-like membrane environment. [5][6][7][8][9][10] While polymer nanodiscs are the youngest of the nanodisc field, they are showing great potential due to the simplicity of their synthesis,their diverse chemical tunability,and their ability to directly extract membrane proteins from their cellular environment at practical cost. [5-7, 9, 11-22] Nanodiscs are au seful tool for NMR spectroscopy since their size can be tuned to conditions favorable to both solution and solid-state NMR.…”

“…Additionally,n anodiscs were shown to align in the presence of the magnetic field which can provide additional useful structural information. [8,19,23] Despite these advantages the fundamental challenges related to poor NMR sensitivity still remain, requiring long acquisition times and high sample concentrations. [24] In this study we focused on the synthesis of an anodisc-forming metal-chelated polymer and its use as ap aramagnetic relaxation enhancement (PRE) system.…”

Magnetic-alignment of polymer macro-nanodiscs enable residual dipolar couplings based high-resolution structural studies by NMR

“…[14][15]20 Furthermore the size control enabled the use of macro-nanodiscs (> 20 nm) in solid-state NMR due to their magnetic alignment properties in the presence of an external magnetic field. [14][15]21 In this study, we exploit the magnetic-alignment property of macro-nanodiscs for high-resolution NMR studies of water-soluble proteins using residual dipolar couplings (RDCs).…”