Amyloid-binding proteins: affinity-based separation, proteomic identification, and optical biosensor validation.

The amyloid-beta peptide is considered as a key player in the development and progression of Alzheimer's disease (AD). Although good evidence exists that amyloid-beta accumulates inside cells, intracellular brain amyloid-beta-binding proteins remain poorly characterized. Here we describe a protocol for affinity-based profiling of amyloid-beta-binding proteins of rat brain, their proteomic identification and validation by a surface plasmon resonance (SPR)-based analysis. It includes: (a) SPR-based selection of immobilization conditions for beta-amyloid coupling and choice of appropriate resin for preparation of an affinity sorbent; (b) immobilization of beta-amyloid on the selected resin;