Aerobic sn-glycerol-3-phosphate dehydrogenase from Escherichia coli binds to the cytoplasmic membrane through an amphipathic alpha-helix.
sn-Glycerol-3-phosphate dehydrogenase (GlpD) from Escherichia coli is a peripheral membrane enzyme involved in respiratory electron transfer. For it to display its enzymic activity, binding to the inner membrane is required. The way the enzyme interacts with the membrane and how this controls activity has not been elucidated. In the present study we provide evidence for direct protein-lipid interaction. Using the monolayer technique, we observed insertion of GlpD into lipid monolayers with a clear preference for anionic phospholipids. GlpD variants with point mutations in their predicted amphipathic helices showed a decreased ability to penetrate anionic phospholipid monolayers. From these data we propose that membrane binding of GlpD occurs by insertion of an amphipathic helix into the acyl-chain region of lipids mediated by negatively charged phospholipids.
Walz
Antje-Christine
AC
Department of Biology, University of Konstanz, 78457 Konstanz, Germany. antje.walz@gmx.de
Demel
Rudy A
RA
de Kruijff
Ben
B
Mutzel
Rupert
R
D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D017931:DNA Primers; D004926:Escherichia coli / Q000201:enzymology*; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism*; D008081:Liposomes; D011485:Protein Binding; D055672:Static Electricity
D017931:DNA Primers; D008081:Liposomes; D005993:Glycerolphosphate Dehydrogenase