Two distinct pools of membrane phosphatidylglycerol in Bacillus megaterium
Autor: | F J Lombardi, A J Fulco |
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Rok vydání: | 1980 |
Předmět: |
Phosphatidylethanolamine
Phosphatidylglycerol biology Phosphatidylethanolamines Phospholipid Phosphatidylglycerols Phosphatidylserine biology.organism_classification Phosphate Microbiology Cerulenin Phosphates Membrane Lipids chemistry.chemical_compound Drug Stability chemistry Biochemistry Bacillus megaterium lipids (amino acids peptides and proteins) Diglyceride Molecular Biology Phospholipids Research Article |
Zdroj: | Journal of Bacteriology. 141:618-625 |
ISSN: | 1098-5530 0021-9193 |
Popis: | The predominant membrane lipid in Bacillus megaterium ATCC 14581, phosphatidylglycerol (PG), is present in two distinct pools, as shown by [32P]phosphate incorporation and chase experiments. One pool (PGt) undergoes rapid turnover of the phosphate moiety, whereas the second pool (PGs) exhibits metabolic stability in this group. The phosphate moiety of the other major phospholipid, phosphatidylethanolamine, is stable to turnover. [32P]phosphate- and [2-3H]glycerol-equilibrated cultures yielded the following glycerolipid composition: 56 mol% PG (34 mol% PGt and 22 mol% PGs), 21 mol% phosphatidylethanolamine, 1 to 2 mol% phosphatidylserine, 20 mol% diglycerides, less than 0.5 mol% cardiolipin, and 0.2 to 0.4 mol% lysophosphatidylglycerol. Accumulation of PG was halted immediately after the addition of cerulenin, an inhibitor of de novo fatty acid synthesis, whereas phosphatidylethanolamine accumulation continued at the expense of the diglyceride and PG pools. Strikingly, initial rates of [32P]phosphate incorporation into PG were unaffected by cerulenin. In control cultures at 35 degrees C, incorporation of [32P]phosphate into PG exhibited a biphasic time course, whereas incorporation into phosphatidylethanolamine was concave upward and lagged behind that of PG during the initial rapid phase of PG incorporation. Finally, levels of lysophosphatidylglycerol expanded rapidly after cerulenin addition at 20 degrees C, but not at 35 degrees C. Moreover, incorporation of [32P]phosphate into lysophosphatidylglycerol lagged behind incorporation into PG in both the presence and absence of cerulenin at 20 and 35 degrees C. |
Databáze: | OpenAIRE |
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