Solubilization of lipids and lipid phases by the styrene-maleic acid copolymer.
A promising tool in membrane research is the use of the styrene-maleic acid (SMA) copolymer to solubilize membranes in the form of nanodiscs. Since membranes are heterogeneous in composition, it is important to know whether SMA thereby has a preference for solubilization of either specific types of lipids or specific bilayer phases. Here, we investigated this by performing partial solubilization of model membranes and analyzing the lipid composition of the solubilized fraction. We found that SMA displays no significant lipid preference in homogeneous binary lipid mixtures in the fluid phase, even when using lipids that by themselves show very different solubilization kinetics. By contrast, in heterogeneous phase-separated bilayers, SMA was found to have a strong preference for solubilization of lipids in the fluid phase as compared to those in either a gel phase or a liquid-ordered phase. Together the results suggest that (1) SMA is a reliable tool to characterize native interactions between membrane constituents, (2) any solubilization preference of SMA is not due to properties of individual lipids but rather due to properties of the membrane or membrane domains in which these lipids reside and (3) exploiting SMA resistance rather than detergent resistance may be an attractive approach for the isolation of ordered domains from biological membranes.
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands. J.J.DominguezPardo@uu.nl.
Juan J
http://orcid.org/0000-0002-8563-2466
JJ
Dominguez Pardo
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands.
Jonas M
JM
Dörr
Nanoscale Biophysics Group, FOM Institute AMOLF, Science Park 104, 1098, Amsterdam, The Netherlands.
Aditya
A
Iyer
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands.
Ruud C
RC
Cox
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands.
Stefan
S
Scheidelaar
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands.
Martijn C
MC
Koorengevel
Nanoscale Biophysics Group, FOM Institute AMOLF, Science Park 104, 1098, Amsterdam, The Netherlands.|Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081, Amsterdam, The Netherlands.
Vinod
V
Subramaniam
Department of Chemistry, Faculty of Science, Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Padualaan 8, 3584, Utrecht, The Netherlands. J.A.Killian@uu.nl.
J Antoinette
JA
Killian
D002462:Cell Membrane / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008298:Maleates / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012995:Solubility
D008051:Lipid Bilayers; D008298:Maleates; D011137:Polystyrenes; C024075:styrofoam; C030272:maleic acid
Lipid rafts; Lipid–protein interactions; Nanodiscs; SMA-resistant membrane (SRM); SMALP; Styrene–maleic acid