著者

Naoki KANEKO Rie YAMAMOTO Taka-Aki SATO Koichi TANAKA

出版者

日本学士院

雑誌

Proceedings of the Japan Academy, Series B (ISSN:03862208)

巻号頁・発行日

vol.90, no.3, pp.104-117, 2014-03-11 (Released:2014-03-11)

参考文献数

41

被引用文献数

10 51 1

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Proteolytic processing of the amyloid precursor protein (APP) by β-secretase and γ-secretase leads to the generation and deposition of amyloid β (Aβ) in Alzheimer’s disease (AD). N-terminally or C-terminally truncated Aβ variants have been found in human cerebrospinal fluid and cultured cell media using immunoprecipitation and mass spectrometry. Unfortunately, the profile of plasma Aβ variants has not been revealed due to the difficulty of isolating Aβ from plasma. We present here for the first time studies of Aβ and related peptides in human plasma. Twenty-two Aβ-related peptides including novel peptides truncated before the β-secretase site were detected in human plasma and 20 of the peptides were identified by tandem mass spectrometry. Using an internal standard, we developed a quantitative assay for the Aβ-related peptides and demonstrated plasma dilution linearity and the precision required for their quantitation. The present method should enhance the understanding of APP processing and clearance in AD progression.

著者

Daniel J. CAPON Naoki KANEKO Takayuki YOSHIMORI Takashi SHIMADA Florian M. WURM Peter K. HWANG Xiaohe TONG Staci A. ADAMS Graham SIMMONS Taka-Aki SATO Koichi TANAKA

出版者

The Japan Academy

雑誌

Proceedings of the Japan Academy, Series B (ISSN:03862208)

巻号頁・発行日

vol.87, no.9, pp.603-616, 2011-11-11 (Released:2011-11-11)

参考文献数

27

被引用文献数

7 7

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There is a significant need for antibodies that can bind targets with greater affinity. Here we describe a novel strategy employing chemical semisynthesis to produce symmetroadhesins: antibody-like molecules having nonprotein hinge regions that are more flexible and extendible and are capable of two-handed binding. Native chemical ligation was carried out under mild, non-denaturing conditions to join a ligand binding domain (Aβ peptide) to an IgG1 Fc dimer via discrete oxyethylene oligomers of various lengths. Two-handed Aβ–Fc fusion proteins were obtained in quantitative yield and shown by surface plasmon resonance to bind an anti-Aβ antibody with a KD at least two orders of magnitude greater than the cognate Aβ peptide. MALDI-TOF MS analysis confirmed the protein/nonprotein/protein structure of the two-handed molecules, demonstrating its power to characterize complex protein-nonprotein hybrids by virtue of desorption/ionization mediated by peptide sequences contained therein. We anticipate many applications for symmetroadhesins that combine the target specificity of antibodies with the novel physical, chemical and biological properties of nonprotein hinges.(Contributed by Koichi TANAKA, M.J.A.)