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Prion protein structure is affected by pH‐dependent interaction with membranes: A study in a model system
Author(s) -
Re Francesca,
Sesana Silvia,
Barbiroli Alberto,
Bonomi Francesco,
Cazzaniga Emanuela,
Lonati Elena,
Bulbarelli Alessandra,
Masserini Massimo
Publication year - 2008
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.2007.12.003
Subject(s) - raft , circular dichroism , chemistry , liposome , membrane , lipid raft , biophysics , ultracentrifuge , ganglioside , sphingomyelin , monomer , biochemistry , recombinant dna , biology , organic chemistry , copolymer , polymer , gene
Interaction of full length recombinant hamster prion protein with liposomes mimicking lipid rafts or non‐raft membrane regions was studied by circular dichroism, chemical cross‐linking and sucrose gradient ultracentrifugation. At pH 7.0, the protein bound palmitoyloleoylphosphatidylcholine/cholesterol/sphingomyelin/monosialoganglioside GM1 (GM1) ganglioside liposomes but not palmitoyloleoylphosphatidylcholine alone (bound/free = 0.33 and 0.01, respectively), maintaining the native α‐helical structure and monomeric form. At pH 5.0, though still binding to quaternary mixtures, in particular GM1, the protein bound also to palmitoyloleoylphosphatidylcholine (bound/free 0.35) becoming unfolded and oligomeric. The pH‐dependent interaction with raft or non‐raft membranes might have implication in vivo, by stabilizing or destabilizing the protein.