Walker Lawrence R, Tfaily Malak M, Shaw Jared B, Hess Nancy J, Paša-Tolić Ljiljana, Koppenaal David W
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, USA.
Metallomics. 2017 Jan 25;9(1):82-92. doi: 10.1039/c6mt00201c.
Under iron-limiting conditions, bacteria produce low molecular mass Fe(iii) binding molecules known as siderophores to sequester the Fe(iii), along with other elements, increasing their bioavailability. Siderophores are thought to influence iron cycling and biogeochemistry in both marine and terrestrial ecosystems and hence the need for rapid, confident characterization of these compounds has increased. In this study, the type of siderophores produced by two marine bacterial species, Synechococcus sp. PCC 7002 and Vibrio cyclitrophicus 1F53, were characterized by use of a newly developed 21 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR MS) with direct injection electrospray ionization. This technique allowed for the rapid detection of synechobactins from Synechococcus sp. PCC 7002 as well as amphibactins from Vibrio cyclitrophicus 1F53 based on high mass accuracy and resolution allowing for observation of specific Fe isotopes and isotopic fine structure enabling highly confident identification of these siderophores. When combined with molecular network analysis two new amphibactins were discovered and verified by tandem MS. These results show that high-field FTICR MS is a powerful technique that will greatly improve the ability to rapidly identify and discover metal binding species in the environment.
在铁限制条件下，细菌会产生低分子量的铁（III）结合分子，即铁载体，以螯合铁（III）以及其他元素，提高它们的生物可利用性。铁载体被认为会影响海洋和陆地生态系统中的铁循环和生物地球化学，因此对这些化合物进行快速、可靠表征的需求日益增加。在本研究中，利用新开发的21 T傅里叶变换离子回旋共振质谱仪（FTICR MS）和直接注射电喷雾电离技术，对两种海洋细菌，聚球藻属PCC 7002菌株和环食弧菌1F53菌株产生的铁载体类型进行了表征。基于高质量精度和分辨率，该技术能够快速检测聚球藻属PCC 7002菌株产生的集球藻素以及环食弧菌1F53菌株产生的两栖菌素，从而能够观察特定的铁同位素和同位素精细结构，实现对这些铁载体的高度可靠鉴定。当与分子网络分析相结合时，通过串联质谱发现并验证了两种新的两栖菌素。这些结果表明，高场FTICR MS是一种强大的技术，将极大地提高快速识别和发现环境中金属结合物种的能力。
