Simultaneously Measured Kinetics of Two Amyloid Polymorphs Using Cross Peak Specific 2D IR Spectroscopy.
J Phys Chem Lett
; 14(51): 11750-11757, 2023 Dec 28.
Article
en En
| MEDLINE
| ID: mdl-38117179
ABSTRACT
The origin of in vitro amyloid fibril polymorphs is debated, in part, because few techniques can simultaneously monitor the formation kinetics of multiple amyloid polymorphs. Using a cross-peak specific polarization scheme, ⟨0°,0°,60°,-60°⟩, we resolve 22 previously unseen cross peaks in the 2D IR spectra of amyloid fibrils formed by the human islet amyloid polypeptide (hIAPP). Those cross peaks include a subset assigned to a second fibril polymorph, which forms on a slower time scale. We simulated the data with three different kinetic models for polymorph formation. Only a model based on secondary nucleation reproduces the cross peak kinetics. These experiments are evidence that fibrils formed by secondary nucleation have a different polymorphic structure than the parent fibrils and illustrate the enhanced structural resolution of this new cross peak specific polarization scheme.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Polipéptido Amiloide de los Islotes Pancreáticos
/
Amiloide
Límite:
Humans
Idioma:
En
Revista:
J Phys Chem Lett
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos