The structure of a ß2-microglobulin fibril suggests a molecular basis for its amyloid polymorphism.
Nat Commun
; 9(1): 4517, 2018 10 30.
Article
em En
| MEDLINE
| ID: mdl-30375379
ABSTRACT
All amyloid fibrils contain a cross-ß fold. How this structure differs in fibrils formed from proteins associated with different diseases remains unclear. Here, we combine cryo-EM and MAS-NMR to determine the structure of an amyloid fibril formed in vitro from ß2-microglobulin (ß2m), the culprit protein of dialysis-related amyloidosis. The fibril is composed of two identical protofilaments assembled from subunits that do not share ß2m's native tertiary fold, but are formed from similar ß-strands. The fibrils share motifs with other amyloid fibrils, but also contain unique features including π-stacking interactions perpendicular to the fibril axis and an intramolecular disulfide that stabilises the subunit fold. We also describe a structural model for a second fibril morphology and show that it is built from the same subunit fold. The results provide insights into the mechanisms of fibril formation and the commonalities and differences within the amyloid fold in different protein sequences.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microglobulina beta-2
/
Amiloide
/
Amiloidose
Tipo de estudo:
Etiology_studies
Limite:
Humans
Idioma:
En
Revista:
Nat Commun
Assunto da revista:
BIOLOGIA
/
CIENCIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Reino Unido