A simple and highly sensitive radioenzymatic assay for lysophosphatidic acid quantification

The objective of the present work was to develop a simple and sensitive rad ioenzymatic assay to quantify lysophosphatidic acid (LPA). For that, a reco mbinant rat LPA acid acyltransferase (LPAAT) produced in Escherichia coli w as used. In the presence of [C-14]oleoyl-CoA, LPAAT selectively catalyzes t he transformation of LPA and alkyl-LPA. into [C-14]phosphatidic acid. Acyla tion of LPA was complete and linear from 0 to 200 pmol with a minimal detec tion of 0.2 pmol. This method was used to quantify LPA in butanol-extracted lipids from bovine sera, as well as from human and mouse plasma. This radi oenzymatic assay represents a new, simple, and highly sensitive method to q uantify LPA in various biological fluids.