Cryo-EM structures of hIAPP fibrils seeded by patient-extracted fibrils reveal new polymorphs and conserved fibril cores.
Nat Struct Mol Biol
; 28(9): 724-730, 2021 09.
Article
in En
| MEDLINE
| ID: mdl-34518699
ABSTRACT
Amyloidosis of human islet amyloid polypeptide (hIAPP) is a pathological hallmark of type II diabetes (T2D), an epidemic afflicting nearly 10% of the world's population. To visualize disease-relevant hIAPP fibrils, we extracted amyloid fibrils from islet cells of a T2D donor and amplified their quantity by seeding synthetic hIAPP. Cryo-EM studies revealed four fibril polymorphic atomic structures. Their resemblance to four unseeded hIAPP fibrils varies from nearly identical (TW3) to non-existent (TW2). The diverse repertoire of hIAPP polymorphs appears to arise from three distinct protofilament cores entwined in different combinations. The structural distinctiveness of TW1, TW2 and TW4 suggests they may be faithful replications of the pathogenic seeds. If so, the structures determined here provide the most direct view yet of hIAPP amyloid fibrils formed during T2D.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cryoelectron Microscopy
/
Islet Amyloid Polypeptide
/
Amyloid
Limits:
Humans
Language:
En
Journal:
Nat Struct Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2021
Type:
Article
Affiliation country:
United States