SMA

Poly(styrene-co-maleic acid) (SMA) is a highly versatile copolymer, containing both hydrophobic moieties (styrene) and reactive, functionalizable moieties. SMA copolymers with different hydrophobicity and solubilization properties can be synthesized by various styrene-to-maleic acid ratios. It is the longest used polymer in the synthetic nanodiscs. SMA can extract membrane proteins directly from their native membrane, while retaining their naturally associated lipids in the form of stable SMA lipid particles (SMALPs). SMA offers several improvements over conventional detergent approaches, however there are limitations, most notably a sensitivity to low pH and divalent cations. To overcome these limitations in using SMAs, there has been emerging research aimed at creating new SMA copolymers by modified maleic acid groups of SMA or other methods. Subsequent research proved that these new SMA copolymers show good results.

Alfa Chemistry offers a wide range of SMA product, including the traditional SMAs and some new SMA copolymers. These products will be available in water solution or powder form at Alfa Chemistry.

Fig. 1. The structure of SMA.

Our Products

Our SMA products can be roughly divided into following three series.

01. This series of products belong to traditional SMAs with various styrene-to-maleic acid ratios. The products are available in lyophilized powder.

Product Name	SMALP 140	SMALP 200	SMALP 300
Structure
Catalog	N-SNP-1	N-SNP-2	N-SNP-3
Physical State	Lyophilized powder, to be solved with water	Lyophilized powder, to be solved with water	Lyophilized powder, to be solved with water
Styrene-to-Maleic Anhydride Ratio	1.4:1	2:1	3:1
Formula Weight	5000 Da	6500 Da	10000 Da
pH	7.5 after solving	7.5 after solving	7.5 after solving
Solubility	45%	40%	35 %
Divalent Cationic Tolerance	<5 mM	<5 mM	<5 mM
Color	Amber	Yellowish	Yellowish
Odor	Odorless	Odorless	Odorless
Available Specification	10 x 50 mg, 1g, 10 x 1 g	10 x 50 mg, 1g, 10 x 1 g	10 x 50 mg, 1g, 10 x 1 g

02. This series of products belong to new SMA copolymers and their full name is poly(styrene-co-maleic acid-co-(N-benzyl)maleimide) copolymer. This series of products are synthesized via RAFT polymerization, achieving a better defined polymer size and a low dispersity (narrow chain length distribution). They are thus more efficient in dissolving the cell membranes and increasing protein yield. All the products are available in lyophilized powder.

Product Name	SMALP BZ25	SMALP BZ30	SMALP BZ35	SMALP BZ40
Catalog	N-SNP-4	N-SNP-5	N-SNP-6	N-SNP-7
Full Name	Poly(styrene-co-maleic acid-co-25%(N-benzyl)maleimide) copolymer, sodium salt in 50 mM HEPES, pH 7.5	Poly(styrene-co-maleic acid-co-30%(N-benzyl)maleimide) copolymer, sodium salt in 50 mM HEPES, pH 7.5	Poly(styrene-co-maleic acid-co-35%(N-benzyl)maleimide) copolymer, sodium salt in 50 mM HEPES, pH 7.5	Poly(styrene-co-maleic acid-co-40%(N-benzyl)maleimide) copolymer, sodium salt in 50 mM HEPES, pH 7.5
Physical State	Lyophilized Powder	Lyophilized Powder	Lyophilized Powder	Lyophilized Powder
Formula Weight	5500 g/mol	5500 g/mol	5500 g/mol	5500 g/mol
pH	7.5	7.5	7.5	7.5
Recommended Concentration Range Upon Use	1% to 5%	1% to 5%	1% to 5%	1% to 5%
Solubility	>10 % in H₂O	>10 % in H₂O	>10 % in H₂O	>10 % in H₂O
Buffer	50 mM HEPES	50 mM HEPES	50 mM HEPES	50 mM HEPES
Color	White to slightly yellow	White to slightly yellow	White to slightly yellow	White to slightly yellow
Odor	Odorless	Odorless	Odorless	Odorless
Available Specification	10 x 50 mg, 1g, 10 x 1 g	10 x 50 mg, 1g, 10 x 1 g	10 x 50 mg, 1g, 10 x 1 g	10 x 50 mg, 1g, 10 x 1 g

03. This series of products also belong to new SMA copolymers. The products are made by modified maleic acid groups of SMA. Because the maleic acid groups of SMA are easily accessible and amenable to modification, enabling the addition of different chemical groups to create new polymers. These products are stable at acidic pH, do not precipitate in the presence of millimolar concentrations of divalent cations. These products will be supplied in water solution or lyophilized powder.

Product Name	SMI	SMA-EA	SMA-ED	SMA-QA	SMAd-A
Structure
Catalog	N-SNP-8	N-SNP-9	N-SNP-10	N-SNP-11	N-SNP-12
Full Name	Poly(styrene-co-maleimide)	SMA-ethanolamine	SMA-ethylenediamine	Styrene maleimide quaternary ammonium copolymer	Dehydrated SMA ethylenediamine copolymer
Physical State	Lyophilized Powder, to be solved with water	Water solution	Water solution	Water solution	Water solution
Styrene-to-Maleic Anhydride Ratio	1.4:1	1:1	1:1	1:1	1:1
Formula Weight	5,000 Da	~7.8 kDa	~7.8 kDa	9 kDa	~7.8 kDa
pH	7.5 after solving		2.0 (1% in water)	5.3 (1% in water)	2.8 (1% in water)
Solubility	38%	≤20% in water	≤20% in water	≤20% in water	≤20% in water
Divalent Cationic Tolerance	>100 mM	-	-	-	-
Color	Yellowish	-	-	-	-
Odor	Odorless	-	-	-	-
Stability	Freeze-thaw stable	-	-	-	-
Available Specification	10 x 50 mg, 1g, 10 x 1 g	250 mg, 500 mg, 1 g	250 mg, 500 mg, 1 g	250 mg, 500 mg, 1 g	250 mg, 500 mg, 1 g

Shiping and Storage

Unless otherwise specified, the shipping temperature of all products is 2-8 °C, and the products can be stored at -20 °C for several years in lyophilized powder form and at 2-8 °C for several days when dissolved.

Alfa Chemistry is pleased to offer SMA products to help our customers conduct their research and achieve more. We guarantee that all our SMA products are of high quality that can be well used in membrane protein study. In addition to the SMA products listed above, we can offer novel variants and derivatives with specific properties designed in on a contract or collaborative basis. If there is any need, please contact us.

Our products and services are for research use only.