Sulfolipid localization in lamellar lipoprotein.

Abstract

The intracellular distribution of lipids in Lemna perpu-silla labeled with C14 revealed that the galactolipids and sulfolipids were specifically localized in the lamellar fragments obtained by sonication of isolated chloroplasts and sedimentation at 145, 000 g for 30 minutes. Major lipids in the lamellar fragments of both Lemna and spinach are galactosyl dilinolenin, digalactosyl dilinolenin, sulfoquinovosyl diglyceride (sulfolipid), and phosphatidyl glycerol. The sulfolipid occurred in the 145, 000 g lamillar lipoprotein fraction of Lemna and not in microsomal or other particulate structures. Lipid and amino-acid composition of ribosome-free lamellar liproprotein is reported. Lecithin, abundant in mitochondria and other membranes, is absent in lamellar lipoprotein. The association of lipids and lamellar protein is interpreted as involving specific hydrophobic interactions between protein and the very characteristic hydrocarbon chains of the lipids.