Fig. 3.
GC-MS profiles of cellular FAMEs extracted from COS-7 cells expressing rat FADS1, FADS2, or FADS3 and incubated with rumenic acid (cis9,trans11-CLA). Control COS-7 cells and COS-7 cells transiently expressing the recombinant FADS proteins were cultivated for 24 h with albumin-bound rumenic acid (200 µM). The identity of each important FA is indicated above its respective peak. It shows that only the cells expressing FADS2 were able to use RA as a substrate. Indeed, detectable amounts of an octadecatrienoic acid (18:3) with FAME molecular ion at m/z 292 amu and Rt = 29.1 min were produced when compared with control cells. Although not fully characterized in the present study, this FA was identified as the cis6,cis9,trans11-18:3, the known Δ6-desaturated product of RA (56–58), by using the NIST database. Representative example of n = 3 distinct experiments.