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Phosphatidic acid plays a special role in stabilizing and folding of the tetrameric potassium channel KcsA
Author(s) -
Raja Mobeen,
Spelbrink Robin E.J.,
de Kruijff Ben,
Killian J. Antoinette
Publication year - 2007
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/j.febslet.2007.11.039
Subject(s) - kcsa potassium channel , tetramer , chemistry , phosphatidic acid , bilayer , crystallography , potassium channel , biophysics , phosphatidylglycerol , dissociation (chemistry) , phosphatidylcholine , biochemistry , ion channel , organic chemistry , phospholipid , receptor , membrane , biology , enzyme
In this study, we investigated how the presence of anionic lipids influenced the stability and folding properties of the potassium channel KcsA. By using a combination of gel electrophoresis, tryptophan fluorescence and acrylamide quenching experiments, we found that the presence of the anionic lipid phosphatidylglycerol (PG) in a phosphatidylcholine (PC) bilayer slightly stabilized the tetramer and protected it from trifluoroethanol‐induced dissociation. Surprisingly, the presence of phosphatidic acid (PA) had a much larger effect on the stability of KcsA and this lipid, in addition, significantly influenced the folding properties of the protein. The data indicate that PA creates some specificity over PG, and that it most likely stabilizes the tetramer via both electrostatic and hydrogen bond interactions.