Evidence for lipid kinase activities in spinach chloroplast envelope membranes

Three spinach chloroplast envelope membrane preparations (i.e. whole, outer and inner membranes) were incubated in the presence of [gamma-32P]ATP. After lipid extraction and separation by TLC, four main phosphorylated lipids were detected by autoradiography in whole envelope preparations. These phospholipids were identified by comparing their Rf with that of lipid markers and by a deacylation procedure. They were found to be phosphatidic acid (PA) and lyso-PA, L-alpha-phosphatidyl-inositol 4-monophosphate (PIP) and lyso-PIP. These lipids were not equally distributed in the outer and inner envelope membranes. Chloroplast envelope membranes were verified not to be contaminated by plasma membranes. It is concluded that lipid kinase activities are associated with spinach chloroplast envelope membranes.