catalog number :
MBS950580
products type :
Recombinant Protein
products full name :
Recombinant Human Proactivator polypeptide
products short name :
Proactivator polypeptide
products name syn :
Proactivator polypeptide
other names :
prosaposin isoform b preproprotein; Prosaposin; prosaposin; prosaposin; Proactivator polypeptide
products gene name :
PSAP
other gene names :
PSAP; PSAP; GLBA; SAP1; GLBA; SAP1; CSAct; SAP-1; SAP-2
uniprot entry name :
SAP_HUMAN
host :
E Coli or Yeast or Baculovirus or Mammalian Cell
sequence positions :
311-391
sequence :
SDVYCEVCEFLVKEVTKLIDNNKTEKEILDAFDKMCSKL
PKSLSEECQEVVDTYGSSILSILLEEVSPELVCSMLHLC
SGT
purity :
Greater than 90% as determined by SDS-PAGE.
form :
Liquid containing glycerol; lyophilization may be available upon request.
storage stability :
Store at -20 degree C, for extended storage, conserve at -20 degree C or -80 degree C.
products categories :
Metabolism
products description :
Saposin-A and saposin-C stimulate the hydrolysis of glucosylceramide by beta-glucosylceramidase (EC 3. 2. 1. 45) and galactosylceramide by beta-galactosylceramidase (EC 3. 2. 1. 46). Saposin-C apparently acts by combining with the enzyme and acidic lipid to form an activated complex, rather than by solubilizing the substrate. Saposin-B stimulates the hydrolysis of galacto-cerebroside sulfate by arylsulfatase A (EC 3. 1. 6. 8), GM1 gangliosides by beta-galactosidase (EC 3. 2. 1. 23) and globotriaosylceramide by alpha-galactosidase A (EC 3. 2. 1. 22). Saposin-B forms a solubilizing complex with the substrates of the sphingolipid hydrolases. Saposin-D is a specific sphingomyelin phosphodiesterase activator (EC 3. 1. 4. 12). Prosaposin: Behaves as a myelinotrophic and neurotrophic factor, these effects are mediated by its G-protein-coupled receptors, GPR37 and GPR37L1, undergoing ligand-mediated internalization followed by ERK phosphorylation signaling.
products references :
Molecular cloning of a human co-beta-glucosidase cDNA
evidence that four sphingolipid hydrolase activator proteins are encoded by single genes in humans and rats.Rorman E.G., Grabowski G.A.Genomics 5:486-492(1989)
ncbi acc num :
NP_001035930.1
ncbi gb acc num :
NM_001042465.2
ncbi pathways :
Class A/1 (Rhodopsin-like Receptors) Pathway (1269545); GPCR Ligand Binding Pathway (1269544); Glycosphingolipid Metabolism Pathway (1270099); Hemostasis Pathway (1269340); Lysosome Pathway (99052); Lysosome Pathway (96865); Metabolism Pathway (1269956); Metabolism Of Lipids And Lipoproteins Pathway (1270001); Peptide Ligand-binding Receptors Pathway (1269546); Platelet Activation, Signaling And Aggregation Pathway (1269350)
ncbi summary :
This gene encodes a highly conserved preproprotein that is proteolytically processed to generate four main cleavage products including saposins A, B, C, and D. Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups. The precursor protein exists both as a secretory protein and as an integral membrane protein and has neurotrophic activities. Mutations in this gene have been associated with Gaucher disease and metachromatic leukodystrophy. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that is proteolytically processed. [provided by RefSeq, Feb 2016]
uniprot summary :
PSAP: The lysosomal degradation of sphingolipids takes place by the sequential action of specific hydrolases. Some of these enzymes require specific low-molecular mass, non-enzymic proteins: the sphingolipids activator proteins (coproteins). Defects in PSAP are the cause of combined saposin deficiency (CSAPD); also known as prosaposin deficiency. CSAPD is due to absence of all saposins, leading to a fatal storage disorder with hepatosplenomegaly and severe neurological involvement. Defects in PSAP saposin-B region are the cause of leukodystrophy metachromatic due to saposin-B deficiency (MLD- SAPB). MLD-SAPB is an atypical form of metachromatic leukodystrophy. It is characterized by tissue accumulation of cerebroside-3-sulfate, demyelination, periventricular white matter abnormalities, peripheral neuropathy. Additional neurological features include dysarthria, ataxic gait, psychomotr regression, seizures, cognitive decline and spastic quadriparesis. Defects in PSAP saposin-C region are the cause of atypical Gaucher disease (AGD). Affected individuals have marked glucosylceramide accumulation in the spleen without having a deficiency of glucosylceramide-beta glucosidase characteristic of classic Gaucher disease, a lysosomal storage disorder. Defects in PSAP saposin-A region are the cause of atypical Krabbe disease (AKRD). AKRD is a disorder of galactosylceramide metabolism. AKRD features include progressive encephalopathy and abnormal myelination in the cerebral white matter resembling Krabbe disease. Defects in PSAP saposin-D region are found in a variant of Tay-Sachs disease (GM2-gangliosidosis). 3 isoforms of the human protein are produced by alternative splicing. Chromosomal Location of Human Ortholog: 10q21-q22. Cellular Component: cytoplasm; extracellular region; extracellular space; integral to membrane; lysosomal lumen; lysosomal membrane; mitochondrion. Molecular Function: enzyme activator activity; G-protein-coupled receptor binding; lipid binding; protein binding. Biological Process: blood coagulation; G-protein signaling, adenylate cyclase inhibiting pathway; glycosphingolipid metabolic process; lipid transport; platelet activation; platelet degranulation; positive regulation of catalytic activity; positive regulation of MAPKKK cascade; regulation of lipid metabolic process; sphingolipid metabolic process. Disease: Combined Saposin Deficiency; Gaucher Disease, Atypical, Due To Saposin C Deficiency; Krabbe Disease, Atypical, Due To Saposin A Deficiency; Metachromatic Leukodystrophy Due To Saposin B Deficiency
size4 :
0.05 mg (Baculovirus)
size5 :
0.05 mg (Mammalian-Cell)