The Peptidoglycan-Associated Lipoprotein (PAL) of the Proteus Mirabilis Outer Membrane: Characterization of the Peptidoglycan-Associated Region of PAL

J Biochem. 1982 Jan;91(1):19-24. doi: 10.1093/oxfordjournals.jbchem.a133675.


The peptidoglycan-associated lipoprotein (PAL) is present in the cell envelope in a form closely, but not covalently, associated with peptidoglycan in various Gram-negative bacteria. When the cell envelope or the isolated peptidoglycan-PAL complex from Proteus mirabilis, in which PAL maintains the interaction with peptidoglycan, was digested with trypsin, a polypeptide fragment with molecular weight 11,000 (11 K fragment) was obtained. However, when isolated PAL or the 11 K-fragment which had been dissociated from peptidoglycan was treated with trypsin, they were further digested. The 11 K-fragment maintained essentially the same tight interaction with peptidoglycan as intact PAL. These results indicate that the 11 K-fragment is probably derived from the peptidoglycan-associated region of the PAL molecule. The purified 11 K-fragment contained neither covalently-linked fatty acid nor glycerylcysteine, which are known to be present at the N-terminus of PAL. The N-terminal sequence of the 11 K-fragment was also determined.

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / analysis
  • Bacterial Outer Membrane Proteins*
  • Cell Wall / analysis
  • Escherichia coli Proteins
  • Lipoproteins / metabolism*
  • Molecular Weight
  • Peptide Fragments / analysis
  • Peptidoglycan / metabolism*
  • Proteoglycans*
  • Proteus mirabilis / analysis*
  • Trypsin


  • Amino Acids
  • Bacterial Outer Membrane Proteins
  • Escherichia coli Proteins
  • ExcC protein, E coli
  • Lipoproteins
  • Peptide Fragments
  • Peptidoglycan
  • Proteoglycans
  • PplA protein, Legionella pneumophila
  • Trypsin