An Efficient Method for the Expression and Purification of Aβ(M1-42).

Advances in amyloid research rely on improved access to the β-amyloid peptide, Aβ. N-Terminal methionine-extended Aβ, Aβ(M1-42), is a readily expressed and widely used form of Aβ with properties comparable to those of the natural Aβ(1-42) peptide. Expression of Aβ(M1-42) is simple to execute and avoids an expensive and often difficult enzymatic cleavage step associated with expression and isolation of Aβ(1-42). This paper reports an efficient method for the expression and purification of Aβ(M1-42) and 15N-labeled Aβ(M1-42). This method affords the pure peptide at ∼19 mg/L of bacterial culture through simple and inexpensive steps in 3 days. This paper also reports a simple method for the construction of recombinant plasmids and the expression and purification of Aβ(M1-42) peptides containing familial mutations. We anticipate that these methods will enable experiments that would otherwise be hindered by insufficient access to Aβ.