Sequential nanopore reading yields single-residue peptide sequencing via tPAL

Researchers introduce transient pore analyte looping (tPAL), pairing a dual-modified MspA nanopore with an NTA-Ni adapter to anchor a peptide for repeated re-reads of the N-terminus. An anchored aminopeptidase then shortens the peptide one amino acid at a time, producing narrow, stepwise, sequence-dependent signals that enable single-amino-acid resolution and detection of mutations, post-translational modifications, and noncanonical amino acids, aided by a machine-learning decoder to reconstruct the sequence.