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Commercial SMA Polymers

The discovery that copolymers composed of styrene and maleic acid groups can solubilize native lipid:protein complexes direct from cells or raw membrane has stimulated a flurry of new research.

Orbiscope  and Cube Biotech offer a range of SMALP products that have been renamed, as announced at the SMALP conference on 1 Oct 2021, to a simpler nomenclature that indicates their subunit ratios. These products have been widely used and are recommended to test and optimize purification of membrane proteins along with bound lipids and partner proteins. Anatrace launched a range of SMA products at the same time, they are stable in high divalent cation concentrations and a wide range of pH values, and allow nanodisc size control.

Product S:MA Ratio† Mw† (g/mole) Source
SMA-EA 1.1:1 7800 Anatrace
SMA-ED 1.1:1 7800 Anatrace
SMA-QA 1.1:1 9000 Anatrace
SMAd-A 1.1:1 7800 Anatrace
SMALP 300 3:1 10000 Orbiscope
SMALP 300 3:1 10000 Cube Biotech
SMALP 200 2.3:1 6500 Orbiscope
SMALP 200 2.3:1 6500 Cube Biotech
SMALP 140 1.4:1 5000 Orbiscope
SMALP 140 1.5:1  7000 Cube Biotech
SMALP 502-E 1.4:1  5000 Cube Biotech
SMALP 140-I 1.4:1 5000 Orbiscope
SMALP 140-I 1.4:1 5000 Cube Biotech
SMALP Screen (4 SMALPs) 5000-10000 Cube Biotech
Nanodisc Screen (8 polymers) 5000-10000 Cube Biotech

Contact or Orbiscope or Cube Biotech for ordering SMALP reagents for your research. Orbiscope sells SMALP reagents with a potassium counter ion (P) while Cube Biotech sell SMALP reagents with a sodium counter ion (S) as ready to use powders. Both are on the same SMA polymeric backbone. The latest to be released in SMALP 502-E, which is designed to increase solubilization yields. Detailed product information can be found in the technical data sheet and will be provided in the certificate of analysis (CoA) supplied with your order.

Other SMA polymers that are commercially available are below.

Product S:MA Ratio† Mw† (g/mole) Source
Lipodisq L8920 2:1 n/a Sigma
Lipodisq L9045 3:1 n/a Sigma
Lipodisq L9170 3:1 n/a Sigma

† The SMA copolymers are defined by the average ratio of styrene to maleic acid repeat units (S:MA). The lengths and blockiness of the polymers is different for each. The number average molecular weight (Mn) is total weight of the polymer molecules divided by the number of molecules. The weight average molecular weight (Mw) is more sensitive to the larger chains present. The polydispersity index (PDI) equals Mw/Mn and is a measure of distribution of the molecular weights.

Related polymers that form native nanodiscs

In addition to SMA polymers, related synthetic copolymers convert membranes into discs and are listed below.

Product Subunit Ratio† Mw† (g/mole) Mn† (g/mole) Source
DIBMA 1:1 15300 8400 Anatrace
DIBMA 10 in HEPES 1:1 10,000   Cube Biotech
DIBMA 10 in Tris 1:1 10,000   Cube Biotech
DIBMA 12 in HEPES 1:1 12,000   Cube Biotech
DIBMA 12 in Tris 1:1 12,000   Cube Biotech
DIBMA 10 & 12 in HEPES 1:1 10K & 12K   Cube Biotech
DIBMA 10 & 12 in Tris 1:1 10K & 12K   Cube Biotech
DIBMA Glycerol in HEPES 1:1 >13,000   Cube Biotech
DIBMA Glycerol in Tris  1:1 >13,000   Cube Biotech
DIBMA Glusoamine in HEPES 1:1 >15,000   Cube Biotech
DIBMA Glusoamine in Tris 1:1 >15,000   Cube Biotech
PMA 1:1.1 n/a n/a Avanti
Sokalan CP9 1:1 15300 8400 BASF

¶ PMA refers to polymethacrylate copolymer product "Nāˆ’C4āˆ’52āˆ’6.9" from Avanti. This belongs to the family of polymers referred to in Yasuhara K, Arakida J, Ravula T, Ramadugu SK, Sahoo B, Kikuchi JI, Ramamoorthy A. 2017. Spontaneous Lipid Nanodisc Fomation by Amphiphilic Polymethacrylate Copolymers. J Am Chem Soc. 139(51):18657-18663.

Anatrace launched their version of purified DIBMA based upon the work of Sandro Keller, and Cube Biotech is offering ready to use DIBMA products in two buffer systems as well as protocols and services. Sokalan CP9 is the tradename of an alternating copolymer of maleic acid and diisobutylene (2,4,4-trimethylpent-1-ene) (DIBMA).

Figure: Polymers developed by the research community for native nanodisc production. 

We welcome you to discuss your thoughts on SMA and related polymers below or by contacting us.