State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China.
Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB E3B 4Z7, Canada.
Biosensors (Basel). 2023 May 26;13(6):581. doi: 10.3390/bios13060581.
Exonuclease III (Exo III) has been generally used as a double-stranded DNA (dsDNA)-specific exonuclease that does not degrade single-stranded DNA (ssDNA). Here, we demonstrate that Exo III at concentrations above 0.1 unit/μL can efficiently digest linear ssDNA. Moreover, the dsDNA specificity of Exo III is the foundation of many DNA target recycling amplification (TRA) assays. We demonstrate that with 0.3 and 0.5 unit/μL Exo III, the degradation of an ssDNA probe, free or fixed on a solid surface, was not discernibly different, regardless of the presence or absence of target ssDNA, indicating that Exo III concentration is critical in TRA assays. The study has expanded the Exo III substrate scope from dsDNA to both dsDNA and ssDNA, which will reshape its experimental applications.
外切核酸酶 III（Exo III）通常被用作一种双链 DNA（dsDNA）特异性的外切核酸酶，不会降解单链 DNA（ssDNA）。在这里，我们证明 Exo III 在浓度高于 0.1 单位/μL 时可以有效地消化线性 ssDNA。此外，Exo III 的 dsDNA 特异性是许多 DNA 靶标循环扩增（TRA）检测的基础。我们证明，在 0.3 和 0.5 单位/μL 的 Exo III 存在下，游离或固定在固体表面上的 ssDNA 探针的降解没有明显差异，无论是否存在靶 ssDNA，这表明 Exo III 浓度在 TRA 检测中至关重要。这项研究将 Exo III 的底物范围从 dsDNA 扩展到 dsDNA 和 ssDNA，这将重塑其实验应用。
