SMPD1 (human, recombinant)

Acid sphingomyelinase, also known as sphingomyelin phosphodiesterase 1 (SMPD1), is a lysosomal and secretory phosphodiesterase.¹ SMPD1, the gene encoding acid sphingomyelinase, produces three isoforms but only the full-length isoform is further processed into a precursor polypeptide, which is composed of an N-terminal signal peptide, a saposin-like (SAP) domain, a proline-rich domain, a metallophosphoesterase catalytic region, and a C-terminal domain. The precursor polypeptide is subject to post-translational modifications and alternative trafficking, which results in two enzymes: lysosomal sphingomyelinase (L-SMase), which is further cleaved to an N-terminus of Gly66, and secretory sphingomyelinase (S-SMase), which is further cleaved to an N-terminus of His60.^1,2 Both enzymes catalyze the hydrolysis of sphingomyelin into ceramide and phosphocholine.¹ Acid sphingomyelinase is ubiquitously expressed and hydrolyzes sphingomyelin in the endo-lysosome, in lipoproteins, and at the outer leaflet of the plasma membrane.^3,1 It has roles in various cellular processes, including apoptosis, immune cell activation, and inflammation.² Mutations in SMPD1 result in type A and B Niemann-Pick disease, a lysosomal storage disorder characterized by sphingomyelin accumulation in the endo-lysosome and visceral, neurological, and psychiatric symptoms.^4,5 Cayman's SMPD1 (human, recombinant) protein can be used for enzyme activity assay applications. This protein consists of 593 amino acids, has a calculated molecular weight of 66.3 kDa, and a predicted N-terminus of Leu47 after signal peptide cleavage.

WARNING This product is not for human or veterinary use.

1. Jenkins, R.W., Canals, D., and Hannun, Y.A. Roles and regulation of secretory and lysosomal acid sphingomyelinase. Cell Signal. 21(6), 836-846 (2009).

2. Xiang, H., Jin, S., Tan, F., et al. Physiological functions and therapeutic applications of neutral sphingomyelinase and acid sphingomyelinase. Biomed. Pharmacother. 139, 111610 (2021).

3. Tani, M., Ito, M., and Igarashi, Y. Ceramide/sphingosine/sphingosine 1-phosphate metabolism on the cell surface and in the extracellular space. Cell Signal. 19(2), 229-237 (2007).

4. Pfrieger, F.W. The Niemann-Pick type diseases - A synopsis of inborn errors in sphingolipid and cholesterol metabolism. Prog. Lipid Res. 90, 101225 (2023).

5. Pinto, C., Sousa, D., Ghilas, V., et al. Acid sphingomyelinase deficiency: A clinical and immunological perspective. Int. J. Mol. Sci. 22(23), 12870 (2021).