Chapter 11. Mass Spectrometry of Membrane Transport Proteins
- Michael W. Quick Ph.D.
Published Online: 19 MAR 2003
Copyright © 2002 by Wiley-Liss, Inc.
How to Cite
Whitelegge, J. P., Kaback, H. R. and le Coutre, J. (2002) Mass Spectrometry of Membrane Transport Proteins, in Transmembrane Transporters (ed M. W. Quick), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471434043.ch11
Department of Neurobiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
- Published Online: 19 MAR 2003
- Published Print: 23 AUG 2002
Book Series Editors:
- David R. Sibley
Series Editor Information
Molecular Neuropharmacology Section, Experimental Therapeutics Branch, NINDS, National Institutes of Health, Bethesda, Maryland, USA
Print ISBN: 9780471065135
Online ISBN: 9780471434047
- membrane protein;
- post-translational modification;
- protein oxidation;
- transport mechanism;
- membrane protein structure
The lactose permease from Escherichia coli is a paradigm for an integral membrane transport protein. Based on liquid-chromatography electrospray ionization mass-spectrometry (LC-ESI-MS) a technology has been developed to characterize the covalent structure of this class of membrane proteins. Accuracy and resolution of the technique permit detection of subtle covalent modifications such as oxidation or alkylation of the protein. Monitoring changes of the molecular weight under defined and specific conditions in combination with site directed mutagenesis is a powerful tool to develop a detailed picture of the transport mechanism on the atomic level. Using inactive single-Cys D240C permease it is demonstrated that the thiol group of C240 can be oxidized via sulfenic and sulfinic acid to a sulfonic acid. Moreover, correlating the time course of oxidation with activity measurements demonstrates that only the sulfinic acid at position 240 is able to mimic the native aspartate with respect to recovery of activity.