Under pathological conditions, the microtubule binding tau protein forms β-structured amyloid aggregates that are involved in several neurodegenerative diseases including Alzheimer’s disease.48 Here we study a 187 amino acid-long, N-terminal truncated human 4R tau that contains residues 255-441, referred to as tau187. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.