Sphingomyelinase Assay Kit - 96 Well

Sphingomyelinase (SMase) is a hydrolase enzyme that is involved in sphingolipid metabolism. SMase is a member of the DNase I superfamily of enzymes and is responsible for the breakdown of sphingomyelin into phosphorylcholine and ceramide. The activation of SMase has been suggested as a major route for the production of ceramide in response to cellular stress. The five distinct types of SMases are classified according to their cation requirements, cellular localization, and pH optima. The types are: Lysosomal Acid SMase, secreted zinc-dependent Acid SMase, a membrane-bound magnesium-dependent Neutral SMase, a cytosolic magnesium-independent Neutral SMase, and an Alkaline SMase. Loss of acidic SMase activity due to a mutation in the acid SMase (ASM) gene results in type A and B Niemann-Pick disease. SMases are important in many physiological and pathophysiological processes, including: 1) lysosomal digestion of sphingomyelin, which is important for normal neuronal and vascular function; 2) ceramide-mediated signal transduction, leading to cytokine-induced apoptosis, cellular differentiation, and various immune and inflammatory responses; 3) lipoprotein aggregation within the vessel wall, which is a key event in atherogenesis and 4) intracellular cholesterol trafficking and metabolism. Cayman`s Sphingomyelinase Assay provides a simple, reproducible, and sensitive tool for assaying neutral and acidic sphingomyelinase activity from tissue homogenates, cell lysates, serum, saliva, and urine. The SMase Assay utilizes a coupled enzymatic reaction to monitor SMase activity. SMase hydrolyzes sphingomyelin to yield ceramide and phosphorylcholine. Alkaline phosphatase hydrolyzes phosphorylcholine forming choline. Choline is then oxidized by choline oxidase to yield betaine and H2O2. Finally, H2O2, in the presence of horseradish peroxidase (HRP), reacts with 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) in a 1:1 stoichiometry to generate the highly fluorescent product resorufin. Resorufin fluorescence is analyzed with an excitation wavelength of 530-540 nm and an emission wavelength of 585-595 nm.Application/Fluorescence, Chemical Class/Assay Kits, Research Area/Atherosclerosis, Research Area/Cell Biology, Research Area/ImmunologySynonyms :SMase Assay Kit