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Updated: Aug 18, 2026

Determining Membrane Protein Topology Using Fluorescence Protease Protection (FPP)
Published on: April 20, 2015
Transmembrane protein topology mapping by the substituted cysteine accessibility method (SCAM(TM)): application to
Mikhail Bogdanov1, Wei Zhang, Jun Xie
1Department of Biochemistry and Molecular Biology, University of Texas-Houston, Medical School, Houston, TX 77030, USA.
Abstract:
We provide an overview of lipid-dependent polytopic membrane protein topogenesis, with particular emphasis on Escherichia coli strains genetically altered in their lipid composition and strategies for experimentally determining the transmembrane organization of proteins. A variety of reagents and experimental strategies are described including the use of lipid mutants and thiol-specific chemical reagents to study lipid-dependent and host-specific membrane protein topogenesis by substituted cysteine site-directed chemical labeling. Employing strains in which lipid composition can be controlled temporally during membrane protein synthesis and assembly provides a means to observe dynamic changes in protein topology as a function of membrane lipid composition.
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