title: Development of a pretreatment method for amyloid beta-protein analysis based on the effect of acetic acid on the dissolution of plasma polypeptides.
abstract: During the evaluation of a pretreatment method for the simultaneous quantification of four amyloid beta-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 beta-protein fragments and plasma polypeptides, which leads to a higher recovery of the amyloid beta-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 beta-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 beta-protein fragments in transgenic mice plasma containing an abundance of plasma polypeptides such as albumin.
authors.affiliation: Drug Metabolism and Pharmacokinetics Research Laboratories, R&D Division, Daiichi Sankyo Co. Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan. goda.ryoya.u4@daiichisankyo.co.jp
authors.forename: Ryoya
authors.initials: R
authors.lastname: Goda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masumoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Okazaki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sudo
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D016229:Amyloid beta-Peptides / Q000097:blood*; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D010455:Peptides / Q000097:blood*; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D016229:Amyloid beta-Peptides; D010455:Peptides; D012997:Solvents; D019342:Acetic Acid