Development of a pretreatment method for amyloid β-protein analysis based on the effect of acetic acid on the dissolution of plasma polypeptides

✍ Scribed by Ryoya Goda; Hiroshi Masumoto; Osamu Okazaki; Kenichi Sudo

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 113 KB
• Volume: 22
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/bmc.1058

✦ Synopsis

Abstract

During the evaluation of a pretreatment method for the simultaneous quantification of four amyloid β‐protein fragments in transgenic mice plasma by a new gradient system, we have found that acetic acid has potency to completely dissolve plasma polypeptides in the presence of an organic solvent. Based on this observation, we designed a simple pretreatment method using an ultrafiltration membrane. An analysis of the filtrate obtained by this method suggests the possibility that acetic acid inhibits the interaction between amyloid β‐protein fragments and plasma polypeptides, which leads to a higher recovery of the amyloid β‐protein fragments from mouse plasma. In addition, higher dilution of mouse plasma using a dilution solution produced higher recovery as well. The highest recovery of amyloid β‐protein 1–38, 1–40, 1–42 and 1–43 fragments was 101.7, 94.9, 96.2 and 84.8%, respectively. Furthermore, calibration curves with the lower limit of quantification of 0.65 nm were successfully constructed with good accuracy using the developed method. Consequently, a pretreatment method using an ultrafiltration membrane is a powerful tool to determine the amyloid β‐protein fragments in transgenic mice plasma containing an abundance of plasma polypeptides such as albumin. Copyright © 2008 John Wiley & Sons, Ltd.