Figure 4.

Protein sequencing based on a nanopore. a) Schematic of peptide sequencing with the assistance of DNA helicase using a nanopore (upper), along with the presentation of typical ion current signals during the test (lower). Reproduced with permission.^{[ 62 ]} Copyright 2021, American Association for the Advancement of Science. b) Schematic of protein identification based on the fingerprint of polypeptide fragments. Reproduced with permission.^{[ 63 ]} Copyright 2022, American Chemical Society. c) Schematic of controlled translocation of protein through an integrated multiprotein complex. Reproduced with permission.^{[ 64 ]} Copyright 2021, Springer Nature.