Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.
Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
Nat Nanotechnol. 2021 Dec;16(12):1362-1370. doi: 10.1038/s41565-021-00979-0. Epub 2021 Oct 21.
Decoding the identity of biomolecules from trace samples is a longstanding goal in the field of biotechnology. Advances in DNA analysis have substantially affected clinical practice and basic research, but corresponding developments for proteins face challenges due to their relative complexity and our inability to amplify them. Despite progress in methods such as mass spectrometry and mass cytometry, single-molecule protein identification remains a highly challenging objective. Towards this end, we combine DNA nanotechnology with single-molecule force spectroscopy to create a mechanically reconfigurable DNA nanoswitch caliper capable of measuring multiple coordinates on single biomolecules with atomic resolution. Using optical tweezers, we demonstrate absolute distance measurements with ångström-level precision for both DNA and peptides, and using multiplexed magnetic tweezers, we demonstrate quantification of relative abundance in mixed samples. Measuring distances between DNA-labelled residues, we perform single-molecule fingerprinting of synthetic and natural peptides, and show discrimination, within a heterogeneous population, between different posttranslational modifications. DNA nanoswitch calipers are a powerful and accessible tool for characterizing distances within nanoscale complexes that will enable new applications in fields such as single-molecule proteomics.
从痕量样本中解码生物分子的身份是生物技术领域的一个长期目标。DNA 分析的进展极大地影响了临床实践和基础研究，但由于蛋白质相对复杂，我们无法对其进行扩增，因此相应的蛋白质分析方法的发展面临挑战。尽管质谱和质谱流式细胞术等方法取得了进展，但单分子蛋白质鉴定仍然是一个极具挑战性的目标。为此，我们结合 DNA 纳米技术和单分子力谱学，创建了一种机械可重构的 DNA 纳米开关卡尺，能够以原子分辨率测量单个生物分子上的多个坐标。我们使用光学镊子演示了对 DNA 和肽的绝对距离测量，具有 Ångström 级精度，并且使用多重磁镊，我们演示了混合样品中相对丰度的定量。通过测量 DNA 标记残基之间的距离，我们对合成和天然肽进行了单分子指纹图谱分析，并在异质群体中显示出不同翻译后修饰之间的区分。DNA 纳米开关卡尺是一种强大且易于使用的工具，可用于表征纳米级复合物内的距离，这将为单分子蛋白质组学等领域的新应用开辟道路。
