Figure 7.

Effect of LPC and acyl-CoA concentrations on microsomal sn-1 acyltransferase activity. A, microsomal homogenates isolated from mouse liver were incubated with 10 μm 18:0-CoA in the presence of increasing concentrations of l-2-AA-ether-LPC for 1 min at 37 °C in 75 mm sodium phosphate buffer (pH 7.4). The reactions were terminated by adding chloroform/methanol (1:1, v/v). Di-14:1-PC was added as an internal standard, and the extraction mixture was vortexed. The chloroform layer was collected and dried under a nitrogen stream. The dried residues were redissolved in water/methanol (1:4), and the sn-1 acyltransferase product, 1-stearoyl-2-AA-ether-PC, was analyzed and quantitated by LC-MS in the positive ion mode. B, microsomal homogenates isolated from mouse liver were incubated with 10 μm l-2-AA-ether-LPC in the presence of increasing concentrations of 18:0-CoA for 2 min at 37 °C in 75 mm sodium phosphate buffer (pH 7.4). The resulting 1-stearoyl-2-AA-ether-PC was extracted and analyzed as described above. Values are the average of four independent preparations. Error bars represent S.E.