title: Structural dynamics associated with intermediate formation in an archetypal conformational disease.
abstract: In conformational diseases, native protein conformers convert to pathological intermediates that polymerize. Structural characterization of these key intermediates is challenging. They are unstable and minimally populated in dynamic equilibria that may be perturbed by many analytical techniques. We have characterized a forme fruste deficiency variant of α(1)-antitrypsin (Lys154Asn) that forms polymers recapitulating the conformer-specific neo-epitope observed in polymers that form in vivo. Lys154Asn α(1)-antitrypsin populates an intermediate ensemble along the polymerization pathway at physiological temperatures. Nuclear magnetic resonance spectroscopy was used to report the structural and dynamic changes associated with this. Our data highlight an interaction network likely to regulate conformational change and do not support the recent contention that the disease-relevant intermediate is substantially unfolded. Conformational disease intermediates may best be defined using powerful but minimally perturbing techniques, mild disease mutants, and physiological conditions.
authors.affiliation: Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London, WC1E 7HX, UK.
authors.forename: Mun Peak
authors.initials: MP
authors.lastname: Nyon
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Segu
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Cabrita
authors.forename: Géraldine R
authors.initials: GR
authors.lastname: Lévy
authors.forename: John
authors.initials: J
authors.lastname: Kirkpatrick
authors.forename: Benoit D
authors.initials: BD
authors.lastname: Roussel
authors.forename: Anathe O M
authors.initials: AO
authors.lastname: Patschull
authors.forename: Tracey E
authors.initials: TE
authors.lastname: Barrett
authors.forename: Ugo I
authors.initials: UI
authors.lastname: Ekeowa
authors.forename: Richard
authors.initials: R
authors.lastname: Kerr
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Waudby
authors.forename: Noor
authors.initials: N
authors.lastname: Kalsheker
authors.forename: Marian
authors.initials: M
authors.lastname: Hill
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Thalassinos
authors.forename: David A
authors.initials: DA
authors.lastname: Lomas
authors.forename: John
authors.initials: J
authors.lastname: Christodoulou
authors.forename: Bibek
authors.initials: B
authors.lastname: Gooptu
mesh_terms: D000939:Epitopes / Q000235:genetics*; D006801:Humans; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D058105:Polymerization; D011487:Protein Conformation; D057165:Proteostasis Deficiencies / Q000235:genetics* / Q000473:pathology; D000515:alpha 1-Antitrypsin / Q000737:chemistry* / Q000235:genetics
chemical_list: D000939:Epitopes; D000515:alpha 1-Antitrypsin