Preferential insertion of lactose permease in phospholipid domains: AFM observations

Laura Picas (1) , Adrian Carretero-Genevrier (2) , M Teresa Montero , J.L. Vázquez-Ibar , Bastien Seantier (3) , Pierre-Emmanuel Milhiet (4) , Jordi Hernández-Borrell , M. Teresa Montero

1 CDC - Compartimentation et dynamique cellulaires
2 ICMAB - Institut de Ciència de Materials de Barcelona
3 IEM - Institut Européen des membranes
4 CBS - Centre de Biochimie Structurale [Montpellier]

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.

Domaines: Biophysique

Laura Picas, Adrian Carretero-Genevrier, M Teresa Montero, J.L. Vázquez-Ibar, Bastien Seantier, et al.. Preferential insertion of lactose permease in phospholipid domains: AFM observations. Biochimica et Biophysica Acta:Biomembranes, 2010, 1798 (5), pp.1014-1019. ⟨10.1016/j.bbamem.2010.01.008⟩. ⟨hal-02289084⟩