Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands.
Nano Lett. 2024 Nov 6;24(44):14118-14124. doi: 10.1021/acs.nanolett.4c04510. Epub 2024 Oct 24.
After the successful sequencing of nucleic acids, nanopore technology has now been applied to proteins. Recently, it has been demonstrated that an electro-osmotic flow can be used to induce the transport of unraveled polypeptides across nanopores. Polypeptide translocation, however, is too fast for accurate reading its amino acid compositions. Here, we show that the introduction of hydrophobic residues into the lumen of the nanopore reduces the protein translocation speed. Importantly, the introduction of a tyrosine at the entry of the nanopore and an isoleucine at the entry of the β-barrel of the nanopore reduced the speed of translocation to ∼10 amino acids/millisecond while keeping a relatively large ionic current, a crucial component for protein identification. These nanopores showed unique features within their current signatures, which may pave the way toward protein fingerprinting using nanopores.
核酸测序成功后，纳米孔技术现在已经应用于蛋白质领域。最近，已经证明可以利用电动渗透流来诱导未展开的多肽穿过纳米孔。然而，多肽的穿膜速度太快，无法准确读取其氨基酸组成。在这里，我们表明，在纳米孔的内腔中引入疏水性残基会降低蛋白质的穿膜速度。重要的是，在纳米孔入口处引入酪氨酸，在β-桶入口处引入异亮氨酸，可将穿膜速度降低到约 10 个氨基酸/毫秒，同时保持相对较大的离子电流，这是蛋白质鉴定的关键组成部分。这些纳米孔在其电流特征中表现出独特的特征，这可能为使用纳米孔进行蛋白质指纹识别铺平道路。
