An online nano-LC-ESI-FTICR-MS method for comprehensive characterization of endogenous fragments from amyloid β and amyloid precursor protein in human and cat cerebrospinal fluid
An online nano-LC-ESI-FTICR-MS method for comprehensive characterization of endogenous fragments from amyloid β and amyloid precursor protein in human and cat cerebrospinal fluid
复制标题
DOI：
10.1002/jms.2987
复制
发表时间：
2012-05-01
影响因子：
2.3
通讯作者：
Brinkmalm, Ann
中科院分区：
文献类型：
--
作者：
Brinkmalm, Gunnar;Portelius, Erik;Brinkmalm, Ann
淀粉样前体蛋白 (APP) 是β淀粉样蛋白 (Aβ) 的前体蛋白，β淀粉样蛋白是阿尔茨海默病 (AD) 中老年斑的主要成分。内源性 Aβ 肽反映了 APP 加工过程，更多地了解不同 APP 降解途径对于理解 AD 病理学的潜在机制非常重要。当通过低能碰撞诱导解离串联质谱 (MS/MS) 分析较长的 A β 肽时，主要观察到长 b 片段，从而限制了确定肽 N 末端一半内的氨基酸变异或翻译后修饰 (PTM) 等变异的可能性。然而，通过使用电子捕获解离 (ECD)，我们获得了多个 APP/A β 肽种类的更全面的序列覆盖，从而能够更深入地表征可能的变异和 PTM。 溶酶体贮积病 C 型尼曼匹克病中也描述了异常的 APP/A β 加工，用于研究这种疾病的主要大型动物是猫。通过 ECD MS/MS，鉴定出了 cat A beta 中的 Asp7 -> Glu 替换。此外，最近在人 Aβ（一种以前未知的糖基化类型）中发现的唾液酸化核心 1（如 Tyr10 处的 O-聚糖）也在猫脑脊液 (CSF) 中被发现。因此，这种不寻常的糖基化类型很可能（至少）对于属于伯氏真目动物的物种来说是常见的。我们在这里通过使用在线自上而下的基于 MS 的方法描述了 CSF 中内源 APP/A β 肽种类的详细表征。版权所有 (C) 2012 约翰·威利父子有限公司
Amyloid precursor protein (APP) is the precursor protein to amyloid beta (A beta), the main constituent of senile plaques in Alzheimer's disease (AD). Endogenous A beta peptides reflect the APP processing, and greater knowledge of different APP degradation pathways is important to understand the mechanism underlying AD pathology. When one analyzes longer A beta peptides by low-energy collision-induced dissociation tandemmass spectrometry (MS/MS), mainly long b-fragments are observed, limiting the possibility to determine variations such as amino acid variants or post-translational modifications (PTMs) within the N-terminal half of the peptide. However, by using electron capture dissociation (ECD), we obtained a more comprehensive sequence coverage for several APP/A beta peptide species, thus enabling a deeper characterization of possible variants and PTMs.Abnormal APP/A beta processing has also been described in the lysosomal storage disease Niemann-Pick type C and the major large animal used for studying this disease is cat. By ECD MS/MS, a substitution of Asp7 -> Glu in cat A beta was identified. Further, sialylated core 1 like O-glycans at Tyr10, recently discovered in human A beta (a previously unknown glycosylation type), were identified also in cat cerebrospinal fluid (CSF). It is therefore likely that this unusual type of glycosylation is common for (at least) species belonging to the magnorder Boreoeutheria. We here describe a detailed characterization of endogenous APP/A beta peptide species in CSF by using an online top-down MS-based method. Copyright (C) 2012 John Wiley & Sons, Ltd.