Department of Food Chemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Allmandring 5b, 70569 Stuttgart, Germany.
J Agric Food Chem. 2022 Sep 21;70(37):11813-11822. doi: 10.1021/acs.jafc.2c03745. Epub 2022 Sep 8.
Patients who suffer from birch pollinosis often develop adverse reactions to the consumption of fresh apples due to the structural similarity of the allergens Bet v 1 and Mal d 1 from birch and apples, respectively. A different allergenic potential for Mal d 1 isoallergens is postulated, but approaches to quantify the Mal d 1 isoallergen-specific are missing. Therefore, a bottom-up proteomics approach was developed to quantify Mal d 1 by stable isotope dilution and microHPLC-QTOF analyses. Marker peptides for individual isoallergens (Mal d 1.01-Mal d 1.03 and Mal d 1.06), combinations thereof (Mal d 1.01 + 1.02, Mal d 1.02 + 1.06, and Mal d 1.04 + 1.05), and two global marker peptides, comprising Mal d 1.01 + 1.02 + 1.04 + 1.05 and Mal d 1.03 + 1.06 + 1.07 + 1.08 + 1.09, were identified. By the use of an extraction standard (r-Mal d 1_mut), an optimized protocol for extraction and tryptic digestion of apple proteins was developed, and the variety-specific extraction efficiency was monitored for the flesh and peel of apples. The Mal d 1 contents in flesh and peel of five commercial apple breeds and four apple varieties from orchard meadows were quantified isoallergen-specific.
桦树花粉过敏患者在食用新鲜苹果时常常会产生不良反应，这是因为桦树中的过敏原 Bet v 1 和苹果中的过敏原 Mal d 1 之间存在结构上的相似性。有人推测 Mal d 1 同种异体过敏原具有不同的致敏潜力，但缺乏定量分析 Mal d 1 同种异体过敏原的方法。因此，本研究采用自下而上的蛋白质组学方法，通过稳定同位素稀释和微 HPLC-QTOF 分析来定量测定 Mal d 1。选择了用于鉴定单个同种异体过敏原（Mal d 1.01-Mal d 1.03 和 Mal d 1.06）、组合同种异体过敏原（Mal d 1.01 + 1.02、Mal d 1.02 + 1.06 和 Mal d 1.04 + 1.05）以及两种全局标记肽（Mal d 1.01 + 1.02 + 1.04 + 1.05 和 Mal d 1.03 + 1.06 + 1.07 + 1.08 + 1.09）的标记肽。通过使用提取标准品（r-Mal d 1_mut），开发了一种优化的苹果蛋白提取和酶切消化方案，并监测了果肉和果皮中苹果的品种特异性提取效率。本研究对五种商业苹果品种和四个果园草地苹果品种的果肉和果皮中的 Mal d 1 含量进行了同种异体特异性定量分析。
