'5D protein fingerprinting' may help treat Alzheimer's

In an advance that could help treat neurodegenerative diseases like Alzheimer's and Parkinson's, scientists have developed a '5D fingerprinting' technique for precisely measuring the properties of individual protein molecules floating in a liquid.

Proteins are essential to the function of every cell. Measuring their properties in blood and other body fluids could unlock valuable information, as the molecules are a vital building block in the body, said researchers at University of Michigan (U-M) in the US.

The body manufactures them in a variety of complex shapes that can transmit messages between cells, carry oxygen and perform other important functions.

Scientists believe that some types of misshapen proteins, called amyloids, can clump together into masses in the brain.

The sticky tangles block normal cell function, leading to brain cell degeneration and disease.

However, the processes of how amyloids form and clump together are not well understood. This is due in part to the fact that there is currently not a good way to study them.

Researchers say current methods are expensive, time-consuming and difficult to interpret, and can only provide a broad picture of the overall level of amyloids in a patient's system.

The researchers at U-M and University of Fribourg in Switzerland who developed the new technique believe that it could help solve the problem by measuring an individual molecule's shape, volume, electrical charge, rotation speed and propensity for binding to other molecules.

They call this information a "5D fingerprint" and believe that it could uncover new information that may one day help doctors track the status of patients with neurodegenerative diseases and possibly even develop new treatments.

"Imagine the challenge of identifying a specific person based only on their height and weight," said David Sept, a U-M biomedical engineering professor who worked on the project.

"That is essentially the challenge we face with current techniques. Imagine how much easier it would be with additional descriptors like gender, hair colour and clothing.

"That's the kind of new information 5D fingerprinting provides, making it much easier to identify specific proteins," said Sept.

Michael Mayer, the lead author on the study and professor at Switzerland's Adolphe Merkle Institute, said identifying individual proteins could help doctors keep better tabs on the status of a patient's disease, and it could also help researchers gain a better understanding of exactly how amyloid proteins are involved with neurodegenerative disease.

To take the detailed measurements, the team uses a nanopore 10-30 nanometres wide - so small that only one protein molecule can fit through at a time.

The researchers filled the nanopore with a salt solution and passed an electric current through the solution.

The research was published in the journal Nature Nanotechnology.