Preparation and characterization of a highly soluble Aβ1-42 peptide variant

Publication date: Available online 16 August 2019Source: Protein Expression and PurificationAuthor(s): Marcia A. LeVatte, Matthias Lipfert, Carol Ladner-Keay, David S. WishartAbstractAlzheimer's disease (AD) is a progressive neurological disease marked by the accumulation and deposition of misfolded amyloid beta or Abeta (Aβ) peptide. Two species of Aβ peptides are found in amyloid plaques, Aβ1-40 and Aβ1-42, with the latter being the more amyloidogenic of the two. Understanding how and why Aβ peptides misfold, oligomerize and form amyloid plaques requires a detailed understanding of their structure and dynamics. The poor solubility and strong aggregation tendencies of Aβ1-42 has made the isolation and characterization of its different structural isoforms (monomer, dimer, oligomer, amyloid) exceedingly difficult. Furthermore, while synthetic Aβ1-42 peptides (Aβ42syn) are readily available, the cost of isotopically labeled peptide is substantial, making their characterization by NMR spectroscopy cost prohibitive. Here we describe the design, cloning, high-level production, isotopic labeling and biophysical characterization of a modified (solubility-tagged) Aβ1-42 variant that exhibits excellent water solubility and shares similar aggregation properties as wildtype Aβ1-42. Specifically, we attached six lysines (6K) to the C-terminus of native Aβ1-42 to create a more soluble, monomeric form of Aβ1-42 called Aβ42C6K. A gene for the Aβ42C6K was designed, synthesized ...
Source: Protein Expression and Purification - Category: Biochemistry Source Type: research