title: Nanodomain Formation of Ganglioside GM1 in Lipid Membrane: Effects of Cholera Toxin-Mediated Cross-Linking.
abstract: Cross-linking of specific lipid components by proteins mediates transmembrane signaling and material transport. In this work, we conducted coarse-grained simulation to investigate the interactions of binding units of chorela toxin (CTB) with mixed ganglioside GM1 and dipalmitoylphosphatidylcholine (DPPC) lipid bilayer membrane. We determine that the binding of CTB pentamers cross-links GM1 molecules into protein-sized nanodomains that have distinct lipid order compared with the bulk. The toxin in the nanodomain partially penetrates into the membrane. The local disordering can also transmit across the membrane via lipid coupling. Comparison simulations on CTB binding to a membrane that is composed of various lipid components demonstrate that several factors are responsible for the nanodomain formation: (a) the negatively charged headgroup of a GM1 receptor is responsible for the multivalent binding; (b) the head groups being full of hydrogen-bonding donors and receptors stabilize the GM1 cluster itself and ensure the toxin binding with high affinity; and
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Huijiao
authors.initials: H
authors.lastname: Sun
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Licui
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Lianghui
authors.initials: L
authors.lastname: Gao
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Weihai
authors.initials: W
authors.lastname: Fang
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002772:Cholera Toxin / Q000737:chemistry*; D005677:G(M1) Ganglioside / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D015060:1,2-Dipalmitoylphosphatidylcholine; D005677:G(M1) Ganglioside; D002772:Cholera Toxin