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Interaction of the K + channel KcsA with membrane phospholipids as studied by ESI mass spectrometry
Author(s) -
Demmers Jeroen A.A.,
van Dalen Annemieke,
de Kruijff Ben,
Heck Albert J.R.,
Killian J.Antoinette
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00282-5
Subject(s) - kcsa potassium channel , phosphatidylglycerol , chemistry , phosphatidylethanolamine , phosphatidylcholine , electrospray ionization , vesicle , mass spectrometry , membrane , chromatography , biophysics , analytical chemistry (journal) , phospholipid , biochemistry , ion channel , biology , receptor
In this study we have used electrospray ionization mass spectrometry (ESI‐MS) to investigate interactions between the bacterial K + channel KcsA and membrane phospholipids. KcsA was reconstituted into lipid vesicles of variable lipid composition. These vesicles were directly analyzed by ESI‐MS or mixed with trifluoroethanol (TFE) before analysis. In the resulting mass spectra, non‐covalent complexes of KcsA and phospholipids were observed with an interesting lipid specificity. The anionic phosphatidylglycerol (PG), and, to a lesser extent, the zwitterionic phosphatidylethanolamine (PE), which both are abundant bacterial lipids, were found to preferentially associate with KcsA as compared to the zwitterionic phosphatidylcholine (PC). These preferred interactions may reflect the differences in affinity of these phospholipids for KcsA in the membrane.