Biomaterial Database

Biochemical, immunological, and structural studies on a sphingolipid activator protein (SAP-1). 1984

K Inui, and D A Wenger

Sphingolipid activator protein-1 (SAP-1) is a glycoprotein found in human tissue extracts that stimulates the enzymatic hydrolysis of at least two glycosphingolipids, including GM1 ganglioside and sulfatide. The ability of purified SAP-1 to stimulate GM1 ganglioside hydrolysis by extracts of cultured fibroblasts from patients with beta-galactosidase deficiency was examined, and all patients had a pronounced deficiency (under 10% of control). Using monospecific antibodies against SAP-1, the concentration was determined in cultured fibroblasts by rocket immunoelectrophoresis. Extracts from 15 control cell lines were found to have 0.72 +/- 0.24 micrograms cross-reactive material/mg protein, while cell extracts from 8 patients with GM1 gangliosidosis involving mental retardation were found to have 1.08 +/- 0.17, which is significantly elevated. When the fibroblast extracts were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by electroblotting, multiple bands were observed. Controls were found to have two major bands with estimated molecular weights of 9000 and 9500, and a minor band at 7800. Extracts from patients with GM1 gangliosidosis were found to have multiple bands ranging upward to 13,000. Extracts from patients with the most severe clinical types of GM1 gangliosidosis had almost exclusively high-molecular-weight forms (molecular weights above 10,000). Treatment of SAP-1 from control liver with endoglycosidase D caused a decrease in the Mr 9500 band and increased in the Mr 7800 band. When SAP-1 from GM1 gangliosidosis liver was treated sequentially with neuraminidase, beta-galactosidase, and endoglycosidase D, almost all of it was converted to the forms found in control human liver.

UI	MeSH Term	Description	Entries
D007122	Immunoelectrophoresis	A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
D007787	Lactose Intolerance	The condition resulting from the absence or deficiency of LACTASE in the MUCOSA cells of the GASTROINTESTINAL TRACT, and the inability to break down LACTOSE in milk for ABSORPTION. Bacterial fermentation of the unabsorbed lactose leads to symptoms that range from a mild indigestion (DYSPEPSIA) to severe DIARRHEA. Lactose intolerance may be an inborn error or acquired.	Lactose Malabsorption,Alactasia,Dairy Product Intolerance,Hypolactasia,Milk Sugar Intolerance,Intolerance, Lactose,Malabsorption, Lactose
D008661	Metabolism, Inborn Errors	Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero.	Inborn Errors of Metabolism,Metabolism Errors, Inborn,Error, Inborn Metabolism,Errors Metabolism, Inborn,Errors Metabolisms, Inborn,Errors, Inborn Metabolism,Inborn Errors Metabolism,Inborn Errors Metabolisms,Inborn Metabolism Error,Inborn Metabolism Errors,Metabolism Error, Inborn,Metabolism Inborn Error,Metabolism Inborn Errors,Metabolisms, Inborn Errors
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D005677	G(M1) Ganglioside	A specific monosialoganglioside that accumulates abnormally within the nervous system due to a deficiency of GM1-b-galactosidase, resulting in GM1 gangliosidosis.	GM1 Ganglioside,Monosialosyl Tetraglycosyl Ceramide,GM1a Monosialoganglioside,Ceramide, Monosialosyl Tetraglycosyl,Ganglioside, GM1,Monosialoganglioside, GM1a,Tetraglycosyl Ceramide, Monosialosyl
D005733	Gangliosidoses	A group of autosomal recessive lysosomal storage disorders marked by the accumulation of GANGLIOSIDES. They are caused by impaired enzymes or defective cofactors required for normal ganglioside degradation in the LYSOSOMES. Gangliosidoses are classified by the specific ganglioside accumulated in the defective degradation pathway.	Ganglioside Storage Diseases,Ganglioside Storage Disorders,Gangliosidosis,Ganglioside Storage Disease,Ganglioside Storage Disorder,Storage Disease, Ganglioside,Storage Diseases, Ganglioside,Storage Disorder, Ganglioside,Storage Disorders, Ganglioside