Redesigned Guide DNA Enhanced <i>Clostridium butyricum</i> Argonaute Activity for Amplification-Free and Multiplexed Detection of Pathogens.

He, Yongqiang; Wang, Shuai; Wen, Junping; Feng, Niu; Ma, Ruxiang; Zhang, Hetong; Chen, Guoxun; Chu, Xiakun et al. · Nano Lett · 2024

basic_science · Level V

Where this comes from

Abstract

<i>Clostridium butyricum</i> (<i>Cb</i>Ago)-based bioassays are popular due to their programmability and directional cleavage capabilities. However, the relatively compact protein structure of <i>Cb</i>Ago limits its cleavage activity (even at the optimal temperature), thus restricting its wider application. Here, we observed that guide DNA (gDNA) with specific structural features significantly enhanced <i>Cb</i>Ago cleavage efficiency. Then, we invented a novel gDNA containing DNAzyme segments (gDNA<sub>zyme</sub>) that substantially enhanced the <i>Cb</i>Ago cleavage efficency (by 100%). Using a molecular dynamics simulation system, we found that the augmented cleavage efficiency might be attributed to the large-scale global movement of the PIWI domain of <i>Cb</i>Ago and an increased number of cleavage sites. Moreover, this gDNA<sub>zyme</sub> feature allowed us to create a biosensor that simultaneously and sensitively detected three pathogenic bacteria without DNA extraction and amplification. Our work not only dramatically expands applications of the <i>Cb</i>Ago-based biosensor but also provides unique insight into the protein-DNA interactions.

Medical subject headings