Summary.
We applied proteomics technologies to analyze a membrane preparation of Escherichia coli, wild type strain and of transformants expressing human cytochrome P450s. The proteins were analyzed by two-dimensional electrophoresis and identified by matrix-assisted laser desorption ionization mass spectrometry. The membrane proteins were solubilized with both mild detergents such as CHAPS and strong detergents, such as sodium and lithium dodecyl sulfate, sodium cholate and sodium deoxycholate. In the E. coli membrane fraction, 394 different gene products were identified. Approximately 28% of them were predicted to be integral membrane proteins, of which 100 proteins have been predicted to carry one transmembrane region, ten proteins to carry two, and two proteins to include three transmembrane domains. The remaining are probably membrane-associated and cytosolic proteins. Cytochrome P450s did not enter the immobilized pH gradient strips but were efficiently analyzed in a two-dimensional, two-detergent system. Use of strong solubilizing agents resulted in the detection of about 20 membrane proteins, which were not detected following extraction with mild detergents and chaotropes. The present database is one of the largest for membrane proteins.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received July 10, 2002 Accepted August 12, 2002 Published online November 20, 2002
Acknowledgments We thank J.-F. Juranville for technical assistance, Drs. S. Evers and E. Nogoceke for critical reading of the manuscript and Dr. H. Langen for helpful discussions.
Authors' address: Michael Fountoulakis, Center for Medical Genomics, F. Hoffmann-La Roche Ltd., Building 93-444, CH-4070 Basel, Switzerland, E-mail: michael.fountoulakis@roche.com
Rights and permissions
About this article
Cite this article
Fountoulakis, M., Gasser, R. Proteomic analysis of the cell envelope fraction of Escherichia coli . Amino Acids 24, 19–41 (2003). https://doi.org/10.1007/s00726-002-0339-z
Issue Date:
DOI: https://doi.org/10.1007/s00726-002-0339-z