| AVS 54th International Symposium | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterials Interfaces Poster Session |
| Presenter: | S. Chemburu, University of New Mexico |
| Authors: | S. Chemburu, University of New Mexico Y. Wu, University of New Mexico K. Ogawa, University of Florida K. Schanze, University of Florida D. Whitten, University of New Mexico G.P. Lopez, University of New Mexico |
| Correspondent: | Click to Email |
Lipoprotein associated phospholipase A2 (Lp-PLA2) is being recognized as a new biomarker for the prognosis and diagnosis of atherosclerotic patients. Lp-PLA2 cleaves the sn-2 acyl bond of glycerol-phospholipids yielding a fatty acid and a lysophospholipid as byproducts, which play an important role in the generation of pro-inflammatory moieties. The assays that have been developed for quantifying its catalytic activity or its concentration are time consuming and involve tedious experimental procedures. We have developed a simple bead based fluorescent assay for the quantification of the catalytic activity of Lp-PLA2. Using the layer-by-layer coating of surfaces approach, borosilicate glass beads (5uM dia) were coated with a cationic fluorescent conjugated polyelectrolyte poly(phenylene ethynylene) (PPE). The polymer-coated beads were then covered by a layer of an anionic lipid bilayer that is a natural substrate for PLA2. The lipid bilayer acted as a barrier protecting the fluorescence of PPE from being quenched by anthraquinone disulfonate (AQS). Upon the addition of PLA2, the hydrolysis of the lipid bilayer is catalyzed exposing the PPE to AQS and hence the fluorescence of PPE is turned off. The decrease in fluorescence quenching of the PPE in the presence of the lipid bilayer by AQS has been termed as frustrated superquenching and the authors have used this to develop a simple assay for the quantification of Lp-PLA2 activity.