Sphingomyelinase (SMase) cleaves sphingomyelin to produce phosphocholine and ceramide. The activation of SMase leads to increased production of ceramide, which acts as a lipid second messenger that induces a variety of cell regulatory phenomena such as apoptosis, cell differentiation, cell proliferation, and sterol homeostasis. There are five distinct types of SMases. Assay Genie's SMase Activity Assay Kit provides a simple and sensitive method for measuring neutral-SMase enzymatic activity using colorimetry (OD 570 nm). Neutral sphingomyelinase (N-SMase) is a Mg2+ sensitive enzyme that can be activated by a host of physiologically relevant and structurally diverse molecules. In this assay, SMase converts sphingomyelin substrate to phosphocholine and ceramide, which is then further utilized to produce an intermediate that reacts with a highly specific probe to generate color. This high-throughput adaptable assay kit can detect sphingomyelinase activity as low as 1.25 mU/ml (~5 µU/mg tissue/cells) in a variety of samples.

Figure: (a) Choline Standard Curve, (b) SMase activity of brain lysate (4.5 mg), Positive Control (1 µl) (c) SMase specific activity in brain lysate. Assays were performed following the kit protocol.