Department of Biochemistry, Faculty of Science, Ege University, 35100 Bornova-İzmir, Turkey.
Department of Biochemistry, Faculty of Science, Ege University, 35100 Bornova-İzmir, Turkey.
Int J Biol Macromol. 2019 May 15;129:91-97. doi: 10.1016/j.ijbiomac.2019.02.030. Epub 2019 Feb 6.
Sarcosine is an amino acid derivative, which is considered as a key metabolite in various metabolic processes. Therefore, simple and sensitive detection methods are needed for further understanding its metabolic role and diagnostic value. In this study, we developed a novel method that meets the need for practical and sensitive detection in a complex medium mimicking urine conditions. For this aim, we selected sarcosine-specific DNA aptamers using graphene oxide-assisted systemic evolution of ligands by exponential enrichment (GO-SELEX). The candidate aptamers were labeled with 6-carboxyfluorescein (6-FAM) at their 5' ends. Two aptamers, namely 9S and 13S produced a significant fluorescence signal upon sarcosine binding. Both aptamers enabled a sensitive analysis with a detection limit of 0.5 pM. The linear detection ranged between 5 pM and 50 μM for 9S aptamer, while 13S aptamer enabled a wider linear detection range between 5 pM and 500 μM. The aptamer-based assay allowed rapid detection with no need for chemical derivatization of sarcosine and sophisticated instruments. Moreover, the aptamer-based assay was free of interference from urea and human serum albumin.
肌氨酸是一种氨基酸衍生物，被认为是各种代谢过程中的关键代谢物。因此，需要简单、灵敏的检测方法来进一步了解其代谢作用和诊断价值。在本研究中，我们开发了一种新方法，满足了在模拟尿液条件的复杂介质中进行实际和灵敏检测的需求。为此，我们使用氧化石墨烯辅助指数富集配体系统进化（GO-SELEX）选择了肌氨酸特异性 DNA 适体。候选适体在 5'端用 6-羧基荧光素（6-FAM）标记。两种适体，即 9S 和 13S，在与肌氨酸结合时产生显著的荧光信号。两种适体都能实现灵敏分析，检测限为 0.5 pM。9S 适体的线性检测范围在 5 pM 到 50 μM 之间，而 13S 适体的线性检测范围在 5 pM 到 500 μM 之间。基于适体的测定法无需对肌氨酸进行化学衍生化和复杂仪器即可实现快速检测。此外，基于适体的测定法不受尿素和人血清白蛋白的干扰。
