ACTIVATION OF LYSINE 2,3-AMINOMUTASE

赖氨酸2，3-氨基变位酶催化L-赖氨酸和L-赖氨酸的相互转化 β-赖氨酸。这一反应是该途径中第一个确定的步骤 允许梭状芽孢杆菌利用赖氨酸作为碳、氮和 能量。梭状芽孢杆菌也使用β-L赖氨酸来生物合成一些 抗生素。大量研究表明，有几种中间体 反应途径中含有以碳为中心的自由基。这样做的目的是 研究是确定酶如何与其辅助因子结合 (吡哆醛磷酸盐，铁硫簇合物[Fe-S]，S- 腺苷蛋氨酸(SAM)产生这些自由基。工作假说 是当电子从[Fe-S]转移到SAM时，SAM均解成 产生蛋氨酸和5‘-脱氧腺苷自由基(5’-da.)这就是 负责启动催化反应。为了测试这个模型， 将使用电子顺磁共振和穆斯堡尔谱仪 评估[Fe-S]在催化过程中氧化状态的变化。 此外，将使用以下工具验证此更改的动力学能力 快速动力学方法。最后，将合成SAM的类似物并 用作[铁-S]与萨姆之间在 裂解事件，以及用于评估5‘-da产生的陷阱。这 所提出的自由基生成系统也存在于核糖核苷酸中 厌氧生长的大肠杆菌的还原酶以及丙酮酸甲酸酯 裂解酶，在这一领域的研究可能为新的方法提供线索 抑制厌氧菌。

Lysine 2,3-aminomutase catalyzes the interconversion of L-lysine and L- beta-lysine. This reaction is the first committed step in the pathway that allows Clostridia to use Lysine as a source of carbon, nitrogen, and energy. Clostridia also use beta-L-lysine for the biosynthesis of a number of antibiotics. Numerous studies indicate that several intermediates on the reaction pathway contain carbon-centered radicals. The purpose of this study is to determine how the enzyme in combination with its cofactors (pyridoxal phosphate, an iron-sulfur cluster [Fe-S], and S- adenosylmethionine (SAM)) generates these radicals. The working hypothesis is that upon electron transfer to SAM from [Fe-S], SAM homolyzes to generate methionine and a 5'-deoxyadenosyl radical (5'-dA.) which is responsible for initiating catalysis. In order to test this model, electron paramagnetic resonance and Mossbauer spectroscopies will be used to assess a change in the oxidation state of the [Fe-S] during catalysis. In addition, the kinetic competence of this change will be verified using rapid kinetics methods. Lastly, analogs of SAM will be synthesized and used as probes for communication between the [Fe-S] and SAM during the cleavage event, as well as traps to assess the production of 5'-dA.. This proposed radical generating system is also present in the ribonucleotide reductase from anaerobically growing E. coli, as well as pyruvate formate lyase, and research in this area may offer clues for new methods of inhibiting anaerobic bacteria.