Proteomic analysis of the Escherichia coli outer membrane

Molloy, MP, Herbert, BR, Slade, MB, Rabilloud, T, Nouwens, AS, Williams, KL and Gooley, AA (2000) Proteomic analysis of the Escherichia coli outer membrane. European Journal of Biochemistry, 267 10: 2871-2881. doi:10.1046/j.1432-1327.2000.01296.x

Author Molloy, MP
Herbert, BR
Slade, MB
Rabilloud, T
Nouwens, AS
Williams, KL
Gooley, AA
Title Proteomic analysis of the Escherichia coli outer membrane
Journal name European Journal of Biochemistry   Check publisher's open access policy
ISSN 0014-2956
Publication date 2000-05-01
Year available 2000
Sub-type Article (original research)
DOI 10.1046/j.1432-1327.2000.01296.x
Open Access Status Not yet assessed
Volume 267
Issue 10
Start page 2871
End page 2881
Total pages 11
Place of publication OXFORD
Language eng
Abstract Outer membrane proteins (OMPs) of Gram-negative bacteria are key molecules that interface the cell with the environment. Traditional biochemical and genetic approaches have yielded a wealth of knowledge relating to the function of OMPs. Nonetheless, with the completion of the Escherichia coli genome sequencing project there is the opportunity to further expand our understanding of the organization, expression and function of the OMPs in this Gram-negative bacterium. In this report we describe a proteomic approach which provides a platform for parallel analysis of OMPs. We propose a rapid method for isolation of bacterial OMPs using carbonate incubation, purification and protein array by two-dimensional electrophoresis, followed by protein identification using mass spectrometry. Applying this method to examine E. coli K-12 cells grown in minimal media we identified 21 out of 26 (80%) of the predicted integral OMPs that are annotated in SWISS-PROT release 37 and predicted to separate within the range of pH 4-7 and molecular mass 10-80 kDa. Five outer membrane lipoproteins were also identified and only minor contamination by nonmembrane proteins was observed. Importantly, this research readily demonstrates that integral OMPs, commonly missing from 2D gel maps, are amenable to separation by two-dimensional electrophoresis. Two of the identified OMPs (YbiL, YeaF) were previously known only from their ORFs, and their identification confirms the cognate genes are transcribed and translated. Furthermore, we show that like the E. coli iron receptors FhuE and FhuA, the expression of YbiL is markedly increased by iron limitation, suggesting a putative role for this protein in iron transport. In an additional demonstration we show the value of parallel protein analysis to document changes in E. coli OMP expression as influenced by culture temperature.
Keyword Escherichia coli
outer membrane proteins
two-dimensional electrophoresis
integral membrane proteins
2-Dimensional Gel-Electrophoresis
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: ResearcherID Downloads - Archived
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