We report on an anomalous X-ray reflectivity study to locate a labelled residue of a membrane protein with respect to the lipid bilayer. From such experiments, important constraints on the protein or peptide conformation can be derived. Specifically, our aim is to localize an iodine-labelled phenylalanine in the SARS E protein, incorporated in DMPC phospholipid bilayers, which are deposited in the form of thick multilamellar stacks on silicon surfaces. Here, we discuss the experimental aspects and the difficulties associated with the Fourier synthesis analysis that gives the electron density profile of the membranes.
Bibliographical noteFunding Information:
Financial support by the DFG through the German–Israel–Palestine trilateral Project SA 7772/6-1 is gratefully acknowledged. We thank the team of ESRF/ID1 for the continuous help during the experiment and T. Schülli for helpful discussions.
- Anomalous scattering
- Lipid-peptide interaction
- SARS E protein