We describe a set of new tools for the detection and quantification of β-N-methylamino-l-alanine (BMAA) which includes a novel stable isotope-labeled BMAA standard (¹³C₃,¹⁵N₂) and a chip-based capillary electrophoresis mass spectrometry platform for separation and detection. Baseline resolution of BMAA from its potentially confounding structural isomers N-2-aminoethylglycine (AEG) and 2,4-diaminobutyric acid (2,4-DAB) is achieved using the chip-based CE-MS system in less than 1 min. Detection and linearity of response are demonstrated across > 3.5 orders of dynamic range using parallel reaction monitoring (PRM). The lower limit of detection and quantification were calculated for BMAA detection at 40 nM (4.8 ng/mL) and 400 nM (48 ng/mL), respectively. Finally, the strategy was applied to detect BMAA in seafood samples purchased at a local market in Raleigh, NC where their harvest location was known. BMAA was detected in a sea scallop sample. Because the BMAA/stable isotope-labeled ¹³C₃,¹⁵N₂-BMAA (SIL-BMAA) ratio in the scallop sample was below the limit of quantification, a semiquantitative analysis of BMAA content was carried out, and BMAA content was estimated to be approximately 820 ng BMAA/1 g of wet scallop tissue. Identification was verified by high mass measurement accuracy of precursor (< 5 ppm) and product ions (< 10 ppm), comigration with SIL-BMAA spike-in standard, and conservation of ion abundance ratios for product ions between BMAA and SIL-BMAA. Interestingly, BMAA was not identified in the free protein fraction but only detected after protein hydrolysis which suggests that BMAA is tightly bound by and/or incorporated into proteins.

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我们描述了一组用于检测和β-的量化的新工具Ñ -methylamino-升丙氨酸（BMAA），其包括新颖的稳定同位素标记BMAA标准（¹³ Ç ₃，¹⁵ Ñ ₂）和基于芯片的毛细管电泳质谱平台，用于分离和检测。从BMAA潜在混淆的结构异构体中基线分离N使用基于芯片的CE-MS系统可在不到1分钟的时间内获得-2-氨基乙基甘氨酸（AEG）和2,4-二氨基丁酸（2,4-DAB）。使用并行反应监测（PRM），可在> 3.5个数量级的动态范围内显示响应的检测和线性。计算BMAA检测的下限分别为40 nM（4.8 ng / mL）和400 nM（48 ng / mL）。最后，该策略被用于检测在北卡罗来纳州罗利市的一个本地市场上购买的海鲜样品中的BMAA，该市场已知其收获地点。在海扇贝样品中检测到BMAA。因为BMAA /稳定的同位素标记的¹³ C ^ ₃，¹⁵ Ñ ₂扇贝样品中的-BMAA（SIL-BMAA）比低于定量极限，对BMAA含量进行了半定量分析，估计BMAA含量约为820 ng BMAA / 1 g湿扇贝组织。通过对前体（<5 ppm）和产物离子（<10 ppm）的高质量测量精度，符合SIL-BMAA尖峰标准以及保留BMAA和SIL-BMAA之间的产物离子的离子丰度比，验证了鉴定结果。有趣的是，未在游离蛋白级分中鉴定出BMAA，而仅在蛋白水解后才检测到，这表明BMAA与蛋白紧密结合和/或掺入蛋白质中。

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