Two research teams have independently obtained atomic-resolution structures of fully formed amyloid-β peptide fibrils that may be involved in Alzheimer’s disease. These fibrils or similar onesform aggregates called “senile plaques” in the brains of patients with the memory- and identity-loss disease.
The fibrils the teams studied are made of a 42-amino-acid peptide, Aβ-42, which is one of two major forms of amyloid-β peptide. It is more neurotoxic, aggregates faster, and is more predominant in senile plaques than the other type, Aβ-40. Scientists have structurally analyzed Aβ-40 fibrils before. But structural analysis of full Aβ-42 fibrils—thought to be the main bad actors in Alzheimer’s disease and therefore the more important of the two types—has been elusive. Rest