The major phospholipid of Escherichia coli, phosphatidylethanolamine, is required for efficient production and secretion of alkaline phosphatase

The major phospholipid of the Escherichia coli membranes-the zwitterion pho sphatidylethanolamine (PE)-is the only phospholipid involved in the formati on of non-bilayer structure of membrane lipids, which is supposed to be nec essary for efficient translocation of secreted proteins across the cytoplas mic membrane. The effect of PE on the production and secretion of alkaline phosphatase has been studied in this work using the mutant strain E: coil A D93, which is unable to synthesize PE. It was shown that this phospholipid is required for the efficient production and secretion of alkaline phosphat ase. The anionic phospholipid cardiolipin in combination with divalent cati ons Mg2+ functionally replaces PE in these processes, participating in the regulation of lipid polymorphism.