Overlooked peptide forms clumps faster than amyloid in lab

P3 is a small protein fragment produced alongside amyloid-beta during the same molecular cleavage process. For decades, it was dismissed as an inactive byproduct. The researchers now show that P3 can form protein clumps (aggregates) even faster than amyloid-beta, and may also damage brain cells. This raises the question of whether the peptide has been unjustly overlooked for years.

Same factory, second product

Both amyloid-beta and P3 are cleaved from the same parent protein. The enzymes involved act at slightly different positions, producing a shorter fragment: P3. Because earlier research found no alarming behaviour in this fragment, it stayed off the radar. The new findings suggest that assessment may need to be revised.

In laboratory conditions, P3 rapidly clumped into structures resembling the plaques characteristic of Alzheimer’s disease. Whether this process occurs the same way in living brains has not yet been established. The study provides a preliminary signal, not definitive proof.

Implications for treatment research

If P3 does contribute to Alzheimer’s, that has implications for the search for treatments. Enormous resources have been invested in drugs targeting amyloid-beta, with mixed results. A second target could offer a complementary strategy.

The findings remain preliminary. Follow-up research is needed to determine whether P3 plays a role outside the lab, and whether targeting it has any therapeutic effect. What is now clear is that the assumption of P3 being harmless is under serious question.

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