Abstract：
Glutamine is under scrutiny regarding its metabolic deregulation linked to energetic reprogramming in cancer cells. Many analytical techniques have been used to better understand the impact of the metabolism of amino acids on biological processes, however only a few are suited to work with complex samples. Here, we report the use of a general dissolution dynamic nuclear polarization (D-DNP) formulation using an unexpensive radical as a multipurpose tool to study glutamine, with insights from enzymatic modelling to complex metabolic networks and fast imaging. First, hyperpolarized [5-13 C] glutamine is used as molecular probe to study the kinetic action of two enzymes: L-asparaginase that has been used as an anti-metabolic treatment for cancer, and glutaminase. These results are also compared with those acquired with another hyperpolarized amino acid, [1,4-13 C] asparagine. Second, we explored the use of hyperpolarized (HP) substrates to probe metabolic pathways by monitoring metabolic profiles arising from hyperpolarized glutamine in E. coli extracts. Finally, a highly concentrated sample formulation is proposed for the purpose of fast imaging applications. We think that this approach can be extended to formulate other amino acids as well as other metabolites and provide complementary insights into the analysis of metabolic networks.
摘要：
谷氨酰胺正在审查其代谢失调与癌细胞中的能量重编程有关。已经使用了许多分析技术来更好地了解氨基酸代谢对生物过程的影响，然而，只有少数适合处理复杂的样本。这里,我们报告了使用通用溶解动态核极化（D-DNP）制剂，使用便宜的自由基作为研究谷氨酰胺的多用途工具，从酶学建模到复杂的代谢网络和快速成像。首先,超极化[5-13C]谷氨酰胺用作分子探针来研究两种酶的动力学作用：L-天冬酰胺酶已被用作癌症的抗代谢治疗，还有谷氨酰胺酶.还将这些结果与另一种超极化氨基酸获得的结果进行比较，[1,4-13C]天冬酰胺。第二,我们通过监测大肠杆菌提取物中超极化谷氨酰胺产生的代谢谱,探索了使用超极化(HP)底物探测代谢途径的方法.最后,为了快速成像应用的目的,提出了高度浓缩的样品制剂。我们认为这种方法可以扩展到配制其他氨基酸以及其他代谢物，并为代谢网络分析提供补充见解。
