Recognition of tau protein glycation with a tailored aerolysin nanopore

Protein glycation is a mark of molecular aging of proteins associated with neurodegenerative, cardiovascular, and metabolic diseases. However, it is difficult to detect protein glycation due to its low-copy number in vivo and the small difference in molecular weights and charges compared with the wild-type version. Nanopore technology is promising for the measurement of protein glycation because it can acquire multiple characteristics of analytes including molecular size, charge, and interactions with nanopore at single-molecule level. The introduction of the glycation sites in the crucial motif of the microtubule binding domain of tau protein is related with Alzheimer's disease. Here, we designed a mutant aerolysin by introducing seven additional arginine residues to enhance the synergistic effects of the electrostatic interaction and hydrogen bonds between the glycated tau peptides and aerolysin nanopore. We found that the glycated tau peptides show deeper and longer current blockages than the wild-type tau peptides, which enables the identification of tau glycation. This initial work offers a new insight into the rational design of biological nanopore for mapping protein glycation, benefiting to advance the knowledge of the role of protein glycation in disease progression, diagnosis and treatment.