Preferential insertion of lactose permease in phospholipid domains: AFM observations.
We report the insertion of a transmembrane protein, lactose permease (LacY) from Escherichia coli (E. coli), in supported lipid bilayers (SLBs) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG), in biomimetic molar proportions. We provide evidence of the preferential insertion of LacY in the fluid domains. Analysis of the self-assembled protein arrangements showed that LacY: (i) is inserted as a monomer within fluid domains of SLBs of POPE:POPG (3:1, mol/mol), (ii) has a diameter of approx. 7.8nm; and (iii) keeps an area of phospholipids surrounding the protein that is compatible with shells of phospholipids.
Picas
Laura
L
Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona (UB), Spain.
Carretero-Genevrier
Adrián
A
Montero
M Teresa
MT
Vázquez-Ibar
J L
JL
Seantier
Bastien
B
Milhiet
Pierre-Emmanuel
PE
Hernández-Borrell
Jordi
J
D004926:Escherichia coli / Q000201:enzymology; D008051:Lipid Bilayers / Q000737:chemistry*; D026901:Membrane Transport Proteins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*
D008051:Lipid Bilayers; D026901:Membrane Transport Proteins; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; D010743:Phospholipids; C057561:1-palmitoyl-2-oleoylphosphatidylethanolamine; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; C021499:lactose permease