School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
Chembiochem. 2021 Apr 16;22(8):1430-1439. doi: 10.1002/cbic.202000721. Epub 2021 Jan 4.
Matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) is widely used for the analysis of biomolecules. Label-assisted laser desorption/ionisation mass spectrometry (LALDI-MS) is a matrix-free variant of MALDI-MS, in which only analytes covalently attached to a laser desorption/ionisation (LDI) enhancer are detected. LALDI-MS has shown promise in overcoming the limitations of MALDI-MS in terms of sample preparation and MS analysis. In this work, we have developed a series of pyrene-based LDI reagents (LALDI tags) that can be used for labelling and LALDI-MS analysis of reducing carbohydrates from complex (biological) samples without the need for additional chemical derivatisation or purification. We have systematically explored the suitability of four pyrene-based LDI enhancers and three aldehyde-reactive handles, optimised sample preparation, and demonstrated the use of LALDI tags for the detection of lactose. We have also exemplified the potential of LALDI tags for labelling carbohydrates in biological samples by direct detection of lactose in cow's milk. These results demonstrate that LALDI-MS is a promising technique for the analysis of reducing carbohydrates in biological samples, and pave the way for the development of LALDI-MS for glycomics and diagnostics.
基质辅助激光解吸/电离质谱（MALDI-MS）广泛用于生物分子的分析。无基质辅助激光解吸/电离质谱（LALDI-MS）是 MALDI-MS 的无基质变体，其中仅检测到共价连接到激光解吸/电离（LDI）增强剂的分析物。LALDI-MS 在克服 MALDI-MS 在样品制备和 MS 分析方面的局限性方面显示出了前景。在这项工作中，我们开发了一系列基于芘的 LDI 试剂（LALDI 标签），可用于标记和 LALDI-MS 分析来自复杂（生物）样品的还原糖，而无需额外的化学衍生化或纯化。我们系统地探索了四种基于芘的 LDI 增强剂和三种醛反应性手柄的适用性，优化了样品制备，并证明了 LALDI 标签可用于检测乳糖。我们还通过直接检测牛奶中的乳糖，说明了 LALDI 标签在生物样品中标记碳水化合物的潜力。这些结果表明，LALDI-MS 是分析生物样品中还原糖的一种很有前途的技术，为开发用于糖组学和诊断的 LALDI-MS 铺平了道路。
