Scientists have developed a self-assembling peptide that forms tiny protein pores capable of detecting disease-related molecules with high sensitivity, according to a study published in Nature Nanotechnology.
The researchers say the system could be used in future biosensors to identify biomarkers linked to conditions such as Parkinson’s disease and motor neuron disease. However, the work is still at an early experimental stage.
What the study found
The team, led by researchers including scientists from Peking University and collaborators, designed a single peptide called pPorA that can spontaneously assemble into α-helical nanopores inside lipid membranes.
These nanopores can exist in two forms—small and large conductance states—and can be tuned by small chemical changes in their structure. Both forms were able to pass ions and detect different types of biological molecules.
The researchers report that the pores could detect sugars, small peptides, and complex disease-related proteins, including α-synuclein, which is strongly linked to Parkinson’s disease.
Detecting Parkinson’s-related proteins
A key focus of the study was α-synuclein, a protein that can misfold and form toxic aggregates in the brain.
Using the larger nanopores, the researchers were able to identify different forms of α-synuclein, including genetic variants linked to disease. The pores produced distinct electrical signals depending on the protein’s shape, charge, and aggregation state.
The system was also able to track how α-synuclein changed over time, from single molecules to larger oligomers and fibrils. These changes are believed to play a central role in neurodegeneration.
High sensitivity at single-molecule level
The nanopores were sensitive enough to detect very low concentrations of biomarkers, including nanomolar levels of disease-related proteins.
Researchers also showed that the pores could distinguish between closely related molecular forms, including peptide enantiomers (mirror-image molecules) and mutated protein variants.
Smaller pores were used to detect shorter disease-related peptides linked to conditions such as amyotrophic lateral sclerosis (ALS) and cell death pathways.
How the technology works
The peptide forms octameric (eight-unit) structures that insert into lipid membranes, creating a tiny channel for ions to pass through.
When a target molecule interacts with the pore, it partially blocks the flow of electrical current. These changes produce a measurable signal that reveals information about the molecule’s size, shape, and charge.
By adjusting the pore size, the researchers were able to “tune” the sensor for different types of biological targets.
What the researchers say
The authors say the work demonstrates a flexible platform for designing nanopores that can be programmed to detect a wide range of disease biomarkers.
They suggest the approach could eventually be used for:
- early disease detection
- monitoring protein aggregation
- screening potential drug treatments
However, they also caution that the findings are based entirely on laboratory experiments and computer simulations.
Limitations and next steps
The study did not involve human samples or clinical testing. The nanopores were tested in controlled laboratory conditions using synthetic systems and purified proteins.
The researchers say further work is needed to improve stability, refine design rules, and test the system in more realistic biological environments.
If successful, the technology could lead to new types of ultra-sensitive diagnostic devices, but practical medical use is still some years away.