Resolving Isomeric Posttranslational Modifications Using a Biological Nanopore as a Sensor of Molecular Shape

Tobias Ensslen, Kumar Sarthak, Aleksei Aksimentiev, Jan C. Behrends

Research output: Contribution to journalArticlepeer-review

Abstract

The chemical nature and precise position of posttranslational modifications (PTMs) in proteins or peptides are crucial for various severe diseases, such as cancer. State-of-the-art PTM diagnosis is based on elaborate and costly mass-spectrometry or immunoassay-based approaches, which are limited in selectivity and specificity. Here, we demonstrate the use of a protein nanopore to differentiate peptides-derived from human histone H4 protein-of identical mass according to the positions of acetylated and methylated lysine residues. Unlike sequencing by stepwise threading, our method detects PTMs and their positions by sensing the shape of a fully entrapped peptide, thus eliminating the need for controlled translocation. Molecular dynamics simulations show that the sensitivity to molecular shape derives from a highly nonuniform electric field along the pore. This molecular shape-sensing principle offers a path to versatile, label-free, and high-throughput characterizations of protein isoforms.

Original languageEnglish (US)
Pages (from-to)16060-16068
Number of pages9
JournalJournal of the American Chemical Society
Volume144
Issue number35
DOIs
StatePublished - Sep 7 2022

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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