The Institute of Biomedical Studies, and the Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798-7348, USA.
Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea.
Arch Biochem Biophys. 2018 May 15;646:16-23. doi: 10.1016/j.abb.2018.03.028. Epub 2018 Mar 24.
Anthrax is caused by Bacillus anthracis, a bacterium that is able to secrete the toxins protective antigen, edema factor and lethal factor. Due to the high level of secretion from the bacteria and its severe virulence, lethal factor (LF) has been sought as a biomarker for detecting bacterial infection and as an effective target to neutralize toxicity. In this study, we found three aptamers, and binding affinity was determined by fluorescently labeled aptamers. One of the aptamers exhibited high affinity, with a K value of 11.0 ± 2.7 nM, along with low cross reactivity relative to bovine serum albumin and protective antigen. The therapeutic functionality of the aptamer was examined by assessing the inhibition of LF protease activity against a mitogen-activated protein kinase kinase. The aptamer appears to be an effective inhibitor of LF with an IC value of 15 ± 1.5 μM and approximately 85% cell viability, suggesting that this aptamer provides a potential clue for not only development of a sensitive diagnostic device of B. anthracis infection but also the design of novel inhibitors of LF.
炭疽是由炭疽芽孢杆菌引起的，这种细菌能够分泌保护性抗原、水肿因子和致死因子等毒素。由于细菌的高分泌水平及其严重的毒性，致死因子（LF）已被用作检测细菌感染的生物标志物和中和毒性的有效靶点。在本研究中，我们发现了三个适体，并通过荧光标记的适体确定了它们的结合亲和力。其中一个适体具有高亲和力，K 值为 11.0±2.7 nM，与牛血清白蛋白和保护性抗原的交叉反应性较低。通过评估对丝裂原活化蛋白激酶激酶的 LF 蛋白酶活性的抑制作用来检测适体的治疗功能。该适体似乎是 LF 的有效抑制剂，IC 值为 15±1.5 μM，细胞活力约为 85%，这表明该适体不仅为炭疽芽孢杆菌感染的敏感诊断设备的开发提供了潜在线索，而且为 LF 的新型抑制剂的设计提供了潜在线索。
