Hydrogen/deuterium exchange-protected oligomers populated during Aß fibril formation correlate with neuronal cell death.
ACS Chem Biol
; 9(11): 2678-85, 2014 Nov 21.
Article
en En
| MEDLINE
| ID: mdl-25265274
The aggregation of the amyloid-ß peptide (Aß) to form fibrils and plaques is strongly associated with Alzheimer's disease (AD). Although it is well established that this process generates neurotoxicity, it is also heterogeneous with a variety of species being formed during the conversion process. This heterogeneity makes it difficult to detect and characterize each of the aggregates formed, which precludes establishing the specific features responsible for the neurotoxicity observed. Here we use pulse-labeling hydrogen-deuterium exchange experiments analyzed by electrospray ionization mass spectrometry (PL-HDX-ESI-MS) to distinguish three ensembles populated during the aggregation of the 40 and 42 residue forms of the Aß peptide, Aß40 and Aß42, on the basis of differences in their persistent structure. Noticeably, two of them are more abundant at the beginning and at the end of the lag phase and are therefore not detectable by conventional assays such as Thioflavin T (ThT). The ensembles populated at different stages of the aggregation process have a surprisingly consistent average degree of exchange, indicating that there are definite structural transitions between the different stages of aggregation. To determine whether an ensemble of species with a given hydrogen exchange pattern correlates with neurotoxicity, we combined PL-HDX-ESI-MS experiments with parallel measurements of the neurotoxicity of the samples under study. The results of this dual approach show that the maximum toxicity correlates with the ensemble comprising HDX protected oligomers, indicating that development of persistent structure within Aß oligomers is a determinant of neurotoxicity.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Biopolímeros
/
Péptidos beta-Amiloides
/
Muerte Celular
/
Neuronas
Idioma:
En
Revista:
ACS Chem Biol
Año:
2014
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Estados Unidos