出版社:American Society for Biochemistry and Molecular Biology
摘要:In the purple membrane (PM) of Halobacterium salinarum is present a phospholipid dimer consisting of sulfo-triglycosyl-diether (S-TGD-1) esterified to the phosphate group of phosphatidic acid (PA), i.e., S-TGD-1-PA, called glycocardiolipin (GlyC) (Corcelli, A., M. Colella, G. Mascolo, F. P. Fanizzi, and M. Kates. A novel glycolipid and phospholipid in the purple membrane. 2000. Biochemistry. 39: 3318–3326). The GlyC content of whole cells, PM, and other cell fractions of H. salinarum have been analyzed. GlyC is a nonabundant phospholipid in H. salinarum cells, and it represents one of the major phospholipids of isolated PM. In this report, we show that a ) GlyC is formed during the isolation of PM, b ) GlyC increase in H. salinarum cells is specifically induced by osmotic shock, and c ) in correspondence with GlyC increase, a decrease of S-TGD-1 levels occurs. The changes in membrane lipid composition observed during the isolation of PM are due to de novo synthesis of GlyC from S-TGD-1.