SMA is short for styrene maleic anhydride. It belongs to a group of synthetic polymers that can form synthetic nanodiscs. These are small-disc shaped complexes that consists of the polymer, phospholipids of the cell membrane and a membrane protein. They find use in life sciences and medicine for membrane protein stabilization & solubilization without the use of detergents. Another synthetic polymer can be used for the same reason is
DIBMA. Both Cube-Biotech and Orbiscope sell the same polymeric SMA backbone for SMALP. We just customized the SMALP’s to make it more convenient to use within biotechnological research. Orbiscope sells a 20 percent solid content SMALP viscous solution in water, while our products are easy to handle powders.
To the SMALP products HEPES and NaCl are added and freeze-dried to obtain a ready to use powder that guarantees a stable pH at 7.5 when used. It has been shown that some SMALP’s do not work at low pH (1). These additional steps result in a sodium counter ion in our SMALP products, in contrast to Orbiscope’s potassium counter ion. That is why Cube Biotech sells SMALP 25010S, 30010S and 40005S.
The product from Cube Biotech can be directly used for your experiments.
Fig. 1: All of our SMALP products come as lyophilized powder. Just add water and you obtain your SMALP product buffered at pH 7.5 in HEPES.
Fig. 2: Schematic depiction of SMA (red) while solubilizing a membrane protein (orange). The Phospholipids (grey) originate from the cell membrane and are therefore the native lipid enviroment of the membrane protein.
SMA Products
All SMAs are delivered as lyophilized powder.
Features - Our Individual SMAs in comparison
| Feature | SMALP
1100I | SMALP
25010S | SMALP
30010S | SMALP
40005S |
| Polymer styrene-to-maleic-anhydride ratio [n:m] | 1.4:1 | 3:1 | 2.3:1 | 1.4:1 |
| Molecular weight | 5,000 Da | 10,000 Da | 6,500 Da | 5,000 Da |
| Form | Lyophilized powder | Lyophilized powder | Lyophilized powder | Lyophilized powder |
| pH | 7.5 | 7.5 | 7.5 | 7.5 |
| Divalent cationic tolerance | > 100 mM | > 5 mM | > 5 mM | > 5 mM |
| Color | Brownish | Colorless | Yellowish | Amber |
| Odor | Odorless | Odorless | Odorless | Odorless |
| Other noteworthy feature | is imidized with DMAPA | | Most commonly used SMA | |
In case you have further questions about our SMA products, feel free to contact us via "contact@cube-biotech.com"
Frequently asked questions - FAQ
| What SMA is the best one to use? |
| This is tricky to answer, as it depends on the membrane protein which SMA performs best. However SMA 30010S is in general the most recommended. Keep in mind that this is no garantee for it to be the best. It is the best in most cases. |
| What are the recommended concentrations of SMA? |
| Mix the solutions as supplied between concentrations of 1-5% SMALP to the total solutions. These conditions can be used as indications. The optimal SMA concentration must be determined seperately for each experiment. |
| How is SMA stored? |
| Store at cool and dry places, protected from direct sunlight. Long-term storage is recommended at 4°C |
| The viscosity of my SMA has decreased, what did happen? |
| This can occur by storing SMA at low temperatures (as recommended!). Simply warm the SMA solution up to room temperature to restore its original viscosity. |
| How do I quantify my protein amount after SMA treatment? |
In contrast to DIBMA SMA absorbs light at 280 nm similar to proteins. Therefore ultraviolet absorption is no option here. However other protein quantification assays are viable options like: - Bicinchoninic Acid (BCA)
- Bradford
- Folin-Lowry in some cases
|
Disclaimer
The use of styrene maleic anhydride copolymer (SMA) products for the manufacturing of styrene maleic acid copolymer - lipid particles (nanodiscs) (SMALP), and the use of SMALP, are covered by one or more of the following patents owned by Malvern Cosmeceutics Limited: US8623414, EP1890675, GB2426703, AU2006253886, JP5142898, IN261468, CN ZL200680018957.2, CA 2611144 and by the University of Birmingham US8754168.
The purchaser is licensed under those patents to use the SMA; for the manufacture of SMALPs and to use SMALPs so manufactured for the purpose of research and development of proteins, including their production (including purification and solubilization), screening, testing, analysis, characterization (including structural analysis and characterization), including for the purpose of drug screening, but not for the purpose of delivery of agents to humans or other animals for therapeutic, diagnostic prophylactic purposes, which uses are specifically prohibited.
References
- Hall, Stephen CL, et al. "An acid-compatible co-polymer for the solubilization of membranes and proteins into lipid bilayer-containing nanoparticles." Nanoscale 10.22 (2018): 10609-10619.
Fig. 2: Schematic depiction of SMA (red) while solubilizing a membrane protein (orange). The Phospholipids (grey) originate from the cell membrane and are therefore the native lipid enviroment of the membrane protein.
