Large-scale purification and biochemical characterization of crystallization-grade porin protein P from Pseudomonas aeruginosa

E. A. Worobee, N. L. Martin, W. D. McCubbin, C. M. Kay, G. D. Brayer, R. E.W. Hancock

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26 Citations (Scopus)


A large-scale purificatio scheme was developed for lipopolysaccharide-free protein P, the phosphate-starvation-inducible outer-membrane porin form Pseudomonas aeruginosa. This highly purified protein P was used to successfully form hexagonal crystals in the presence of n-octyl-β-glucopyranoside. Amino-acid analysis indicated that protein P had a similar composition to other bacteriol outer membrane proteins, containing a high percentage (50%) of hydrophilic residues. The amino-terminal sequence of this protein, although not homologous to either outer membrane protein, PhoE or OmpF, of Escherichia coli, was found to have an analogous protein-folding pattern. Protein P in the native trimer form was capable of maintaining a stable functional trimer after proteinase cleavage. This suggested the existence of a strongly associated tertiary and quaternary structure. Circular dichroism studies confirmed these results in that a large proportion of the protein structure was determined to be β-sheet and resistant to acid pH and heating in 0.1% sodium dodecyl sulphate.

Original languageEnglish
Pages (from-to)366-374
Number of pages9
JournalBBA - Biomembranes
Issue number2
Publication statusPublished or Issued - 7 Apr 1988
Externally publishedYes


  • (P. aeruginosa)
  • 4-(2-hydroxyethyl)-l-piperazineethane-sulphonic acid
  • Hepes
  • Porin
  • Protein P
  • Protein purification
  • Protein structure

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

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