title: Cofactor molecules induce structural transformation during infectious prion formation.
abstract: The spread of misfolded proteins may occur in many neurodegenerative diseases. Mammalian prions are currently the only misfolded proteins in which high specific biological infectivity can be produced in vitro. Using a system that generates infectious prions de novo from purified recombinant PrP and conversion cofactors palmitoyl-oleoyl-phosphatidylglycerol (POPG) and RNA, we examined by deuterium exchange mass spectrometry (DXMS) the stepwise protein conformational changes that occur during prion formation. We found that initial incubation with POPG causes major structural changes in PrP involving all three α helices and one β strand, with subsequent addition of RNA rendering the N terminus highly exposed. Final conversion into the infectious PrP(Sc) form was accompanied by globally decreased solvent exposure, with persistence of the major cofactor-induced conformational features. Thus, we report that cofactor molecules appear to induce major structural rearrangements during prion formation, initiating a dynamic sequence of conformational changes resulting in biologically active prions.
authors.affiliation: Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Miller
authors.forename: Daphne W
authors.initials: DW
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Geoffrey P
authors.initials: GP
authors.lastname: Noble
authors.forename: Jiyan
authors.initials: J
authors.lastname: Ma
authors.forename: Virgil L
authors.initials: VL
authors.lastname: Woods
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.forename: Surachai
authors.initials: S
authors.lastname: Supattapone
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D041961:Deuterium Exchange Measurement; D051379:Mice; D008969:Molecular Sequence Data; D010715:Phosphatidylglycerols / Q000737:chemistry; D018620:PrPSc Proteins / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012313:RNA / Q000737:chemistry
chemical_list: D010715:Phosphatidylglycerols; D018620:PrPSc Proteins; D012313:RNA; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol