Membrane Solubilization by Styrene-Maleic Acid Copolymers: Delineating the Role of Polymer Length.

Styrene-maleic acid (SMA) copolymers have attracted interest in membrane research because they allow the solubilization and purification of membrane-spanning proteins from biological membranes in the form of native-like nanodisks. However, our understanding of the underlying SMA-lipid interactions is hampered by the fact that SMA preparations are very polydisperse. Here, we obtained fractions of the two most commonly used SMA preparations: SMA 2:1 and SMA 3:1 (both with specified M ∼10 kD), with different number-average molecular weight (M) and styrene content.