Amid Biosciences

Saposin A, Human, Recombinant

Description

Human lysosomes contain four homologous saposins (sphingolipid activator proteins), the saposins A, B, C, and D, which are derived from the prosaposin precursor protein (1, 2).

Saposin A is small, cysteine-rich α-helical glycoprotein that exists in both soluble and lipid-bound states. Saposin A has roles in sphingolipid catabolism and transport and is required for the breakdown of galactosylceramide by β-galactosylceramidase to produce ceramide and galactose (3).

Saposins are glycosylated in a native state; however, non-glycosylated recombinant saposins produced in E. coli retain their respective activation effects in functional in vitro assays (2). Saposins are used as scaffolding proteins in a versatile lipid nanoparticle system to reconstitute membrane proteins in a lipid environment. Saposin-based nanoparticles may have a wide range of potential applications, from structural biology to the therapeutic delivery of protein-based pharmacological agents and vaccines (4).

Recombinant human saposin A is produced in E. coli as an N-terminal His-tag fusion and purified by proprietary chromatography techniques with subsequent removal of the tag trough a site-specific proteolytic cleavage.

Saposin A sequence

SMGSLPCDICKDVVTAAGDMLKDNATEEEILVYLEKTCDWLPKPNMSASCKEIVDSYLPVILDIIKGEMSRPGEVCSALNLCES

Catalog # SAPA-301

Storage buffer: 50 mM Tris-HCl, pH 7.5, 50 mM NaCl, and 50% Glycerol.
Concentration: 1.0 – 2.0 mg/mL by A280 (E^1% 9.3).
Purity: >90% by Coomassie staining

Storage is recommended at -20°C for longer periods of time.

International Shipping: Product requires shipping on ice packs. Please contact info@amidbiosciences.com for shipment estimates

This product is for laboratory research use only.

Product Manual

Safety Data Sheet for Saposin A, Human, Recombinant

References

Qi, X. Differential membrane interactions of saposins A and C: implications for the functional specificity. J Biol Chem. 2001 Jul 20; 276(29): 27010-7.

Qi, X. et al. Functional human saposins expressed in Escherichia coli. Evidence for binding and activation properties of saposins C with acid beta-glucosidase. J Biol Chem. 1994 Jun 17; 269(24):16746-53.

Popovic, K. et al. Structure of saposin A lipoprotein discs. Proc Natl Acad Sci U S A. 2012 Feb 21; 109(8):2908-12. https://doi.org/10.1073/pnas.1115743109

Frauenfeld, J. et al. A saposin-lipoprotein nanoparticle system for membrane proteins. Nat Methods. 2016 Apr; 13(4): 345–351.

Lyons, J. et al. Saposin-Lipoprotein Scaffolds for Structure Determination of Membrane Transporters. Methods Enzymol. 2017; 594:85-99.