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客戶采用我司鏈霉親和素磁珠（PuriMag G-Strep）在《Sensors and Actuators B: Chemical》發(fā)表SCI文章

S1 nuclease digestion-based rational truncation of PD-L1 aptamer and establishment of a signal dual amplification aptasensor

Sensors and Actuators B: Chemical ( IF 7.100 ) Pub Date : 2021-01-08 , DOI: 10.1016/j.snb.2021.129442
Hongwei Hu, Yujing Ding, Zihan Gao, Hao Li

Truncation optimization of aptamers can improve both specificity and robustness. At present, aptamer truncation is mainly performed based on predictions from molecular docking simulations, but this usually requires tedious trial-and-error and may result in false predictions. Here, we propose a strategy based on digestion by S1 nuclease to rationally truncate the aptamer, using the PD-L1-binding aptamer Apt80 as an example. Due to steric hindrance, recognition and binding regions between Apt80 and PD-L1 are not digested by the enzyme. The truncated form, Apt38, shows higher affinity and larger conformational change after binding, when compared to Apt80. The truncated Apt38 was used as a platform for developing a signal dual ampli?cation fluorescence aptasensor using targeted recycling assisted by exonuclease I and qRT-PCR analysis. This aptasensor exhibited a high sensitivity toward PD-L1 with a limit of detection of 0.076 ng/mL in buffer system and 0.3625 ng/mL in human serum. Owing to its high sensitivity, specificity, ease operation and low cost for detection of PD-L1, this aptasensor should be useful in assisting clinicians to evaluate the status of cancer patient and to decide whether inhibitor drugs are needed.

中文翻譯：
基于S1核酸酶消化的PD-L1適體的合理截斷和信號雙重擴增適體傳感器的建立

適體的截短優(yōu)化可以提高特異性和魯棒性。目前，適體截短主要基于分子對接模擬的預(yù)測來進行，但這通常需要乏味的反復(fù)試驗，并且可能導(dǎo)致錯誤的預(yù)測。在這里，我們提出一個基于S1核酸酶消化的策略，以PD-L1結(jié)合適體Apt80為例，合理地截斷適體。由于空間位阻，Apt80和PD-L1之間的識別和結(jié)合區(qū)不會被酶消化。與Apt80相比，結(jié)合后的截短形式Apt38顯示出更高的親和力和更大的構(gòu)象變化。截短的Apt38用作平臺，用于通過核酸外切酶I和qRT-PCR分析輔助的靶向回收來開發(fā)信號雙擴增熒光適體傳感器。該適體傳感器對PD-L1表現(xiàn)出高靈敏度，在緩沖液系統(tǒng)中的檢出限為0.076 ng / mL，在人血清中的檢出限為0.3625 ng / mL。由于其靈敏度高，特異性強，操作簡便且檢測PD-L1成本低，該適體傳感器應(yīng)有助于協(xié)助臨床醫(yī)生評估癌癥患者的狀況并決定是否需要抑制劑藥物。

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