Journal of Lipid Research, Vol 21, 1053-1057, Copyright © 1980 by Lipid Research, Inc.
An improved procedure for the synthesis of 14C-labeled phosphatidylserine from cerebral phosphatidic acid
P Orlando, G Ippolito, L Binaglia, C Giordano and G Porcellati
A complete procedure to prepare a highly labeled phosphatidyl-L-[U-
14C]serine possessing the same fatty acid composition of brain
phospholipids is reported. CDP-diglyceride was synthesized by reaction
between phosphatidic acid and CMP-morpholidate as the
dicyclohexylcarboxamidium salt. The reaction between CDP-diglyceride and
L-[U-14C]serine to produce the labeled phosphatidylserine was catalyzed by
the CDP-diglyceride: L-serine phosphatidyl transferase (EC 2.7.8.8) from E.
coli. A selective inhibition of phosphatidylserine decarboxylase activity,
present as contaminant in the enzyme extract, was introduced in order to
avoid a low yield of product. Traces of phosphatidylethanolamine (about 1%)
were easily removed by preparative thin-layer chromatography. The yield of
the labeled product was as high as 87% and it specific radioactivity was
170 mCi/mmol.