Novel Purification Process for Amyloid Beta Peptide(1-40)

Kenji Usui,Kazuya Iwata,Shin-Ichiro Yokota,Yoshio Hamada

doi:10.3390/pr8040464

Abstract

Amyloid beta peptide (Aβ)-related studies require an adequate supply of purified Aβ peptide. However, Aβ peptides are “difficult sequences” to synthesize chemically, and low yields are common due to aggregation during purification. Here, we demonstrate an easier synthesis, deprotection, reduction, cleavage, and purification process for Aβ(1-40) using standard 9-fluorenylmethyloxycarbonyl (Fmoc)-protected amino acids and solid-phase peptide synthesis (SPPS) resin [HMBA (4-hydroxymethyl benzamide) resin] that provides higher yields of Aβ(1-40) than previous standard protocols. Furthermore, purification requires a similar amount of time as conventional purification processes, although the peptide must be cleaved from the resin immediately prior to purification. The method described herein is not limited to the production of Aβ(1-40), and can be used to synthesize other easily-oxidized and aggregating sequences. Our proposed methodology will contribute to various fields using “difficult sequence” peptides, such as pharmaceutical and materials science, as well as research for the diagnosis and treatment of protein/peptide misfolding diseases.

Highlights

Protein misfolding diseases are increasingly common in aging populations and include Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease
In Alzheimer’s disease (AD) [3,4], amyloid beta peptide (Aβ) forms fibrillar aggregates known as amyloid fibrils [5,6], which are the principal component of extracellular deposits and are the likely causative agent of AD
We we demonstrate demonstrate an an easier easier synthesis, synthesis, deprotection, deprotection, reduction, reduction, cleavage, cleavage, and and purification purification process for

Summary

Introduction

Protein misfolding diseases are increasingly common in aging populations and include Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease. These diseases involve the systematic or tissue-localized deposition of fibrillar, β-sheet-rich protein/peptide assemblies [1,2]. In Alzheimer’s disease (AD) [3,4], amyloid beta peptide (Aβ) forms fibrillar aggregates known as amyloid fibrils [5,6], which are the principal component of extracellular deposits and are the likely causative agent of AD. Recent studies have implicated Aβ and its ability to self-assemble as key factors in the pathogenesis of AD. Aβ-related studies require an adequate supply of purified Aβ peptide.

Methods

Results

Conclusion