3D Blockage Mapping for Identifying Familial Point Mutations in Single Amyloid‐β Peptides with a Nanopore.

Accurate discrimination of amyloid‐β (Aβ) peptides containing familial point mutations would advance the knowledge of their roles in early‐onset Alzheimer's disease. Herein, we simultaneously identified the mutant A21G, E22G, E22Q, and the wild‐type (WT) Aβ18–26 peptides with aerolysin nanopore using a 3D blockage mapping strategy. The standard deviation of current blockade fluctuations (σb) was proposed as a new supplement to current blockage (Ib/I0) and duration time (tD) to profile the blockage characteristics of single molecules. Although the WT and A21G Aβ18‐26 are indistinguishable in a traditional Ib/I0‐tD 2D description, ∼87 % of the blockade events can be accurately classified with half reduction of false identification using a combination of Ib/I0, tD, and σb. This work offers an easy and reliable strategy to promote nanopore sensitivity of peptide mutants, leading to a more precise analysis of pathogenic mutations for developing effective diagnosis and treatment. [ABSTRACT FROM AUTHOR]