NG-Hydroxy-L-arginine (NOHA) is a stable intermediate product in the urea cycle that can be used to monitor the consumption of L-arginine by nitrous oxide synthase (NOS) to produce nitric oxide (NO) and L-citrulline. Research has implicated the urea cycle in many diseases and NO has cultivated interest as a potential biomarker for neural health. Electrochemical detection is an established, cost-effective method that can successfully detect low levels of analyte concentrations. As one of the few electrochemically active species in the urea cycle, NOHA shows promise as a biomarker for monitoring disruptions in this biochemical process. In this study, we show that NOHA has an oxidation peak at +355 mV vs Ag/AgCl at a glassy carbon electrode. In addition, cyclic voltammetry studies with structural analogs - alanine and N-hydroxyguanidine - allowed us to approximate the oxidation wave at +355 mV vs Ag/AgCl to be a one electron process. Diffusivity of NOHA was found using linear scan voltammetry with a rotating disk electrode and approximated at 5.50×10-5 cm2/s. Ample work is still needed to make a robust biosensor, but the results here characterize the electrochemical activity and represent principle steps in making a NOHA biosensor.

中文翻译：

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阐明 NG-羟基-L-精氨酸的电化学机制


NG-羟基-L-精氨酸 (NOHA) 是尿素循环中稳定的中间产物，可用于监测一氧化二氮合酶 (NOS) 产生一氧化氮 (NO) 和 L-瓜氨酸时消耗 L-精氨酸。研究表明尿素循环与许多疾病有关，并且一氧化氮作为神经健康的潜在生物标志物引起了人们的兴趣。电化学检测是一种既定的、经济高效的方法，可以成功检测低浓度的分析物。作为尿素循环中为数不多的电化学活性物质之一，NOHA 显示出作为监测该生化过程中断的生物标志物的前景。在本研究中，我们表明 NOHA 在玻碳电极上相对于 Ag/AgCl 具有 +355 mV 的氧化峰。此外，使用结构类似物（丙氨酸和 N-羟基胍）的循环伏安法研究使我们能够将相对于 Ag/AgCl 的 +355 mV 的氧化波近似为单电子过程。 NOHA 的扩散率是使用带有旋转圆盘电极的线性扫描伏安法测定的，近似为 5.50×10-5 cm2/s。制造稳健的生物传感器仍需要大量工作，但此处的结果表征了电化学活性，并代表了制造 NOHA 生物传感器的主要步骤。