Recombinant Human SMPD1 Protein, CF

Sphingomyelin phosphodiesterase, also known as acid sphingomyelinase and encoded by the SMPD1 gene, is a lysosomal phosphodiesterase which belongs to the acid sphingomyelinase family (1). SMPD1 catalyzes the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. Ceramide, a bioactive lipid, has emerged as an important signaling molecule involved in a variety of cellular processes such as cell differentiation, apoptosis, and proliferation (2). Activation of SMPD1 occurs by the removal, chemical modification or dimerization of its C-terminal cysteine residue (3). Deficiencies of SMPD1 result in a lysosomal storage disorder referred to as Niemann-Pick disease (4). Recombinant human SMPD1 was expressed without the last three C-terminal residues, and is therefore constitutively active.