Prenyl lipid and fatty-acid synthesis in isolatedAcetabularia chloroplasts.

摘要: A gentle procedure allowed the isolation of intact and highly active chloroplasts from unicellular green algaAcetabularia mediterranea. These incorporated carbon NaH(14)CO3 into fatty acids prenyl lipids at a rate about 20-50 nmol carbon· (mg chlorophyll)(-1)·h(-1). Most formed in vitro were esterified galactolipids. The main synthesized chlorophyll side chain, intermediates carotenogenic path, α-and β-carotene, as well lutein. Large amounts [1-(14)C]acetate incorporated, but exclusively acids.Isopentenyl diphosphate was good substrate for prenyl-lipid formation hypotonically treated chloroplasts. envelope chloroplasts, however, impermeable to this compound. Intermediates mevalonate pathway not accepted precursors under conditions whereisopentenyl incorporated. results show that lipid biosynthetic pathways plastids ofAcetabularia, member ancient family Dasycladaceae, are very similar those higher-plant plastids.