Expression of N-Terminal Cysteine Aβ and Conjugation to Generate Fluorescent and Biotinylated Aβ.

Fluorescent derivatives of the β-amyloid peptides (Aβ) are valuable tools for studying the interactions of Aβ with cells. Facile access to labeled expressed Aβ offers the promise of Aβ with greater sequence and stereochemical integrity, without impurities from amino acid deletion and epimerization. Here, we report methods for the expression of Aβ with an N-terminal cysteine residue, Aβ, and its conjugation to generate Aβ bearing fluorophores or biotin.