Polymorph-specific kinetics and thermodynamics of β-amyloid fibril growth.

ABSTRACT: Amyloid fibrils formed by the 40-residue β-amyloid peptide (Aβ(1-40)) are highly polymorphic, with molecular structures that depend on the details of growth conditions. Underlying differences in physical properties are not well understood. Here, we investigate differences in growth kinetics and thermodynamic stabilities of two Aβ(1-40) fibril polymorphs for which detailed structural models are available from solid-state nuclear magnetic resonance (NMR) studies. Rates of seeded fibril elongation in the presence of excess soluble Aβ(1-40) and shrinkage in the absence of soluble Aβ(1-40) are determined with atomic force microscopy (AFM). From these rates, we derive polymorph-specific values for the soluble Aβ(1-40) concentration at quasi-equilibrium, from which relative stabilities can be der

SUBMITTER: Qiang W 

PROVIDER: S-EPMC3686096 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature