FIGURE 12.
LPC as donor in transacylation activity. Radioactive lipids formed in incubations of microsomes (40 μg of protein) prepared from ale1Δ gpc1Δ expressing ScGPCAT. [14C]Glycerol-labeled GPC (0.2 mm) and non-radioactive 18:1-LPC or ricinoleoyl-LPC (ric-LPC) (0.1 mm) or an equimolar mixture of both (0.05 + 0.05 mm) for 30 min. Incubations with microsomes prepared from ale1Δ gpc1Δ strain transformed with empty vector gave no incorporation of radioactivity into the chloroform phase. A, results shown are from triplicate assays ± S.D. (error bars). B, relative distribution of molecular species of PC formed. PC from triplicate assays (A) were pooled before phospholipase C treatment to obtain DAG for separation of molecular species (see “Experimental Procedures”). 0-OH-X and 1-OH-X, lipids with no ricinoleoyl groups and one ricinoleoyl group, respectively.