The versatility of membrane proteins and their composition mirrors the intricate nature of the cell membrane. As a result, it is a challenge to predict with absolute certainty the optimal SMALP BZ polymer for the solubilization and subsequent stabilization of your membrane protein of interest.
Therefore, we offer the SMALP BZ Screening Kit that consists of our four individual SMALP BZs. This way you can conveniently screen for the best SMALP BZ for your protein before scaling up your assay. In case you would like to extend your polymer screening beyond the reaches of SMALP, we offer our Synthetic Nanodisc Screening MAXI, which covers both SMA, DIBMA, and other polymers.
The SMALP BZ series was developed in collaboration with Prof. Bert Klumperman from Nanosene, a spinout company of Stellenbosch University in South Africa. The goal was to create SMALPs that are synthesized via RAFT polymerization, achieving a better-defined polymer size and a low dispersity (narrow chain length distribution). This is a significant improvement over previous SMALPs. The SMALP BZs are thus more efficient in dissolving the cell membranes and increasing protein yield.
After successful solubilization of the membrane protein, the protein can be purified using affinity chromatography. For membrane protein purification we recommend using the Rho1D4-tag. Cube Biotech offers matching products for this purpose.
Poly(styrene-co-maleic acid-co-X%(N-benzyl)maleimide) copolymer, sodium salt in 50 mM HEPES, pH 7.5 X is be replaced with the number in the products name
Formula Weight
5,500 g/mol
Buffer
50 mM HEPES
pH
7.5
State
Lyophilized Powder
Recommended concentration range upon use
1% to 5%
Solubility
> 10 % in H2O
Color
White to slightly yellow
Odor
Odorless
Shipping Temperature
2-8°C
Long-term Storage (lyophilized copolymer)
-20°C for several years
Short-term Storage (dissolved copolymer)
2-8°C for several days
Lab Results
Figure 1: Shown is the blot activity of a Rho1d4-Tag purified full-length human GPCR expressed in HEK cells. The GPCR was solubilized using SMALP BZ25 – 40 as well as SMALP 200 and Sulfo-SMA as control. The isolation blot reveals SMALP BZ40 as copolymer for most efficient purification.
Figure 2: Shown is the blot activity of a Rho1d4-Tag purified unmodified human membrane protein expressed in HEK cells containing one transmembrane helix. The membrane protein was solubilized using SMALP BZ25 to 40 as well SMALP 200 as control. Even though the solubilization blot points to SMALP BZ40 and SMALP 200 as copolymer of choice, the isolation blot reveals SMALP BZ25 as copolymer for most efficient purification.
Figure 3: General structure of the SMALP BZ-Polymers.
Figure 4: Chart of the increasing hydrodrophobicity of the SMALP BZ polymer series.
The increase of the ratio of N-benzylmaleimide in the polymer chain increases the hydrophobicity of the polymers and thus leads to different interaction patterns with the cell membrane. And as different membrane proteins prefer different membrane environments, each level of hydrophobicity is optimal for the solubilization of different membrane proteins. This changing of the ratio of N-benzylmaleimide is what differentiates the SMALPs BZ25 (25%), BZ30 (30%), BZ35 (35%) and BZ40 (40%).
Video
Watch our video on the use of synthetic polymers for membrane protein solubilization. It demonstrates the use with SMALP.
The difference lies in the amount of (N-benzyl)maleimide) in their structure. As you can see in this figure: The ratio of the (N-benzyl)maleimide part is called "a". This number varies between different SMALP BZs. For example SMALP BZ25 carries the (N-benzyl)maleimide ring in 25% of its monomeres. SMALP BZ30 in 30% and so on. This is meant to adapt the different SMALP BZs to different membrane environments.
Are the SMALP BZs from Cube Biotech ready to use?
Yes, all SMALP BZs are ready to use. You can start directly with the solubilization. Read our protocol for more information.
Which pH is suitable for SMALP BZs?
For all SMALP BZs a pH of 7.5 is recommended.
Which concentrations of the SMALP BZs should I use for my protein?
In general, we advise you to add 2,5 % the chosen SMALP BZ to your solution. But the optimal conditions have to be screened by yourself. In general you should not go below 1% or over 5%. Please refer to our Membrane Protein Solubilization Protocol for more information. Or simply ask our support team.
Disclaimer
Patent Pending
The purchaser is licensed under those patents to use the SMALP BZ25; for the manufacture of lipid
particles and to use SMALP BZ25 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.
