Evaluation of fluorescent and colored phosphatidylcholine analogs as substrates for the assay of phospholipase A2.

Two fluorescent phospholipid analogs, 1-O-[12-(2-naphthyl)-dodec-11-enyl]-2-O-decanoyl-sn-glycero-3-phos phocholine and dansyl-PC [rac 1-O-(N-dansyl-11- amino-1-undecyl)-2-O-decanoyl-glycero-3-phosphocholine], and a red-colored analog, dabsyl-PC [rac 1-O-(N-dabsyl-11-amino-1-undecyl)-2-O-decanoyl-glycero-3- phosphocholine], were evaluated as substrates for the assay of phospholipase A2 (PLA2) (Crotalus adamanteus). The assay reaction was monitored by separation of the fluorescent or colored substrate and product by TLC and quantitation by fluorescence or absorption scanning. All three substrates gave similar (within an order of magnitude) activities with PLA2. Dansyl-PC was best suited to this TLC assay. Dabsyl-PC was less sensitive to detection by absorbance, but had the advantage of being red colored and readily detected by the unaided eye.