Department of Chemistry and Biochemistry, University of Denver, Denver, CO, United States.
Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, United States.
Methods Enzymol. 2024;702:317-352. doi: 10.1016/bs.mie.2024.07.001. Epub 2024 Jul 20.
Microorganisms, plants, and animals alike have specialized acquisition pathways for obtaining metals, with microorganisms and plants biosynthesizing and secreting small molecule natural products called siderophores and metallophores with high affinities and specificities for iron or other non-iron metals, respectively. This chapter details a novel approach to discovering metal-binding molecules, including siderophores and metallophores, from complex samples ranging from microbial supernatants to biological tissue to environmental samples. This approach, called Native Metabolomics, is a mass spectrometry method in which pH adjustment and metal infusion post-liquid chromatography are interfaced with ion identity molecular networking (IIMN). This rule-based data analysis workflow that enables the identification of metal-binding species based on defined mass (m/z) offsets with the same chromatographic profiles and retention times. Ion identity molecular networking connects compounds that are structurally similar by their fragmentation pattern and species that are ion adducts of the same compound by chromatographic shape correlations. This approach has previously revealed new insights into metal binding metabolites, including that yersiniabactin can act as a biological zincophore (in addition to its known role as a siderophore), that the recently elucidated lepotchelin natural products are cyanobacterial metallophores, and that antioxidants in traditional medicine bind iron. Native metabolomics can be conducted on any liquid chromatography-mass spectrometry system to explore the binding of any metal or multiple metals simultaneously, underscoring the potential for this method to become an essential strategy for elucidating biological metal-binding molecules.
微生物、植物和动物都有专门的获取途径来获取金属，微生物和植物分别合成并分泌小分子天然产物，称为铁载体和金属载体，它们对铁或其他非铁金属具有高亲和力和特异性。本章详细介绍了一种从复杂样品中发现金属结合分子（包括铁载体和金属载体）的新方法，这些样品范围从微生物上清液到生物组织到环境样品。这种方法称为原生代谢组学，是一种质谱方法，其中在液相色谱后进行 pH 调整和金属输注，并与离子身份分子网络（IIMN）接口。这种基于规则的数据分析工作流程可根据定义的质量（m/z）偏移量以及相同的色谱轮廓和保留时间来识别金属结合物质。离子身份分子网络通过其碎片模式连接结构相似的化合物，以及通过色谱形状相关性连接同一化合物的离子加合物的化合物。这种方法以前揭示了金属结合代谢物的新见解，包括耶尔森菌素除了已知的作为铁载体的作用外，还可以作为生物锌载体；最近阐明的 lepotchelin 天然产物是蓝细菌的金属载体；以及传统医学中的抗氧化剂结合铁。原生代谢组学可以在任何液相色谱-质谱系统上进行，以探索任何金属或多种金属的结合情况，这突显了该方法成为阐明生物金属结合分子的重要策略的潜力。
