Substrate-Specific Inhibition Constants for Phospholipase A₂ Acting on Unique Phospholipid Substrates in Mixed Micelles and Membranes Using Lipidomics.

ABSTRACT: Assaying lipolytic enzymes is extremely challenging because they act on water-insoluble lipid substrates, which are normally components of micelles, vesicles, and cellular membranes. We extended a new lipidomics-based liquid chromatographic-mass spectrometric assay for phospholipases A₂ to perform inhibition analysis using a variety of commercially available synthetic and natural phospholipids as substrates. Potent and selective inhibitors of three recombinant human enzymes, including cytosolic, calcium-independent, and secreted phospholipases A₂ were used to establish and validate this assay. This is a novel use of dose-response curves with a mixture of phospholipid substrates, not previously feasible using traditional radioactive assays. The new application of lipid

SUBMITTER: Mouchlis VD 

PROVIDER: S-EPMC6398150 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature