Detection of intrinsically disordered peptides by biological nanopore

Intrinsically disordered protein regions (IDPRs) are pivotal in the regulation of transcription and the facilitation of signal transduction. Because of their multiple conformational states of structure, characterizing the highly flexible structures of IDPRs becomes challenging. Herein, we employed the wild-type (WT) aerolysin nanopore as a real-time biosensor for the identification and monitoring of long peptides containing IDPRs. This sensor successfully identified three intrinsically disordered peptides, with the lengths up to 43 amino acids, by leveraging the unique signatures of blockade current and translocation duration time. The analysis of the binding constant revealed that interactions between the nanopore and peptide are critical for peptide translocation, suggesting that mechanisms beyond mere volume exclusion are at play. Furthermore, by examining the detailed current traces of blockade events, we were able to compare the conformational stabilities of various IDPRs. Our approach can detect the conformational changes of IDPR in a confined nanopore space. These insights broaden the understanding of peptide structural changes under the confined space. This nanopore biosensor showed the potential to study the conformations change of IDPRs, IDPRs transmembrane interactions, and protein drug discovery.