Membrane Phospholipid Composition of Escherichia coli Affects Secretion of Periplasmic Alkaline Phosphatase into the Medium

A. O. Badyakina, Yu. A. Koryakina, N. E. Suzina, and M. A. Nesmeyanova^*

Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia; fax: (095) 956-3370; E-mail: aniram@ibpm.serpukhov.su

^* To whom correspondence should be addressed.

Received June 4, 2002; Revision received October 23, 2002

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Secretion of alkaline phosphatase (PhoA) encoded by a gene constituent of plasmids has been studied in Escherichia coli strains with controlled synthesis of anionic phospholipids (phosphatidylglycerol and cardiolipin, strain HDL11) and zwitterionic phospholipid (phosphatidylethanolamine, strain AD93). Changing the phospholipid composition of the membrane of these strains leads to an increase in secretion of PhoA, which is usually localized in the periplasm, into the culture medium. This correlates with a higher secretion of exopolysaccharides and lower content of lipopolysaccharide in the outer membrane. The results show the possibility of coupling protein secretion into the medium with biogenesis of cell envelope components in which phospholipids are involved.

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KEY WORDS: Escherichia coli, alkaline phosphatase, secretion, phospholipids, outer membrane

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